Cendio are proud to present ThinLinc 4.21.0, with more than 100 enhancements and fixes. The most prominent changes are:
ThinLinc Web Access now supports the OpenID Connect authentication protocol. This enables organizations to delegate authentication to solutions like Keycloak or Microsoft Entra ID, allowing convenient single sign-on, and more flexibility in authentication methods and policy.
ThinLinc session logs are now in the system journal instead of in xinit.log in the ThinLinc session directories. This avoids multiple log locations for modern Linux systems, and gives more flexibility when analyzing logs.
It is now possible to configure the ThinLinc client with mandatory settings on managed endpoint devices. These settings will be forced and cannot be overridden by the user.
The Linux ThinLinc client now supports 64-bit ARM (ARM64), replacing the previous 32-bit ARM client. This improves compatibility with modern ARM hardware and operating systems.
The platform requirements for the ThinLinc client on macOS have been raised. It now requires macOS Ventura (version 13) or newer. Users on older versions of macOS will need to upgrade their operating system to use this version of the ThinLinc client.
ThinLinc works on most modern Linux distributions and is supported on any platform that fulfills our documented requirements.
In the list below, the bug number is given in parentheses. For more information, visit https://bugzilla.cendio.com.
Patched a security vulnerability which could allow a user to bypass a ForceCommand set to thinlinc-login and still gain remote shell access. (8825)
The ThinLinc server will no longer accept licenses issued on different subscription agreements. The ThinLinc server will pick the most appropriate agreement if such a conflict arises. (8742, 8871)
The ThinLinc server will now more clearly warn both administrators and users about the expiration of ThinLinc licenses. (8866, 8869)
ThinLinc session logs are now in the system journal instead of in xinit.log in the ThinLinc session directories. (5486)
The internal communication between ThinLinc nodes are now version checked. This clarifies the requirement that all nodes in a cluster need to run the same version of ThinLinc. (5679, 8780)
Agent servers in a cluster will now reject communication from a local duplicate master service running on the same machine. This change makes sure that the real master node for the cluster can maintain a consistent state. (8878)
Fixed an issue where the server setup would hang when installing the thinlocal and nearest printer queues on Ubuntu 26.04. (8891)
Added a password confirmation step when setting a password for Web Administration during the server setup. (5944)
Fixed an issue where the server setup failed on Debian/Ubuntu systems using ufw as firewall. (8759)
Fixed an issue where it was not possible to start new sessions on Fedora 42 and subsequent releases because of a bug in the Fedora SELinux policy. (8727)
Fixed an issue where the configured login background would not always be shown. (8212)
Fixed an issue where both the ThinLinc client and server incorrectly logged warnings about incorrect SSH host keys. (8536, 8857)
The desktop shortcuts for ThinLinc setup, ThinLinc Web Access and ThinLinc web administration have been removed. (8392)
The ThinLinc setup now uses colors to emphasize the most important parts of the output when it runs in fallback text mode. (8858)
The ThinLinc setup now allows you to configure the parameter /vsmagent/master_hostname when setting up an agent-only node. (4709)
A Linux client for 64-bit ARM platforms has been added. This improves compatibility with modern hardware and operating systems. The 64-bit ARM client replaces the older 32-bit ARM client, which has been removed. (6978, 8833)
The ThinLinc client now supports adding multiple key files for public key authentication. As a result, the interface for configuring keys has been changed. (8663)
It is now possible to configure the ThinLinc client with mandatory settings on managed endpoint devices. These settings will be forced and cannot be overridden by the user. (5567)
The ThinLinc client for macOS now requires macOS Ventura (version 13) or newer. The ThinLinc server remains backwards compatible with older clients, for those users who cannot upgrade in the near future.
Windows 11 no longer shows a warning about an unknown publisher when installing the ThinLinc client. (8483)
All binaries in the ThinLinc client for Windows and the client customizer are now signed, not just the installers. This provides more protection against malicious tampering and provides compatibility with Windows Smart App Control. (4433, 6991, 8777)
Debug level is now configurable using the new tlclient.conf parameter DEBUG_LEVEL or through the new "Troubleshooting" tab in the options dialog. (8329)
The "Troubleshooting" options tab now provides a quick-access button to the log file folder using the native file manager of the local system. (8843)
Fixed an issue in the ThinLinc client for Linux where the ThinLinc session would resize incorrectly when reconnecting, causing application windows to move. This issue was a regression introduced in ThinLinc 4.19.0. (8686)
The ThinLinc client for macOS has an updated icon to match Apple's "liquid glass" design language. (8767)
The ThinLinc client now supports exporting audio input and output independently. (8193)
Patched a low severity security vulnerability which under certain circumstances might allow an attacker, that is able to modify the ThinLinc client username through the commandline, to execute code on the client machine. [CVE-2025-61984, CVE-2026-35386] (8838)
It is now possible to configure ThinLinc Web Access to allow users to log in using an OpenID Connect provider. (8247)
The Web Access login API has now been documented, making automated logins from web portals easier. (5231)
Fixed a security vulnerability where a user could bypass the authentication policy when reconnecting. Note that the vulnerability only allowed a user to reconnect to their own sessions. (8782)
Improved compatibility with some smart card applications, primarily FreeRDP-based applications such as Remmina. (8817)
A refresh button was added to ThinLinc web administration's Status/Sessions page to allow immediate refresh of session information. (8864)
The duration a session has been disconnected is now directly shown in the sessions list in both ThinLinc web administration and tlctl. (8820)
Added a new subcommand "tlctl license usage" that can display peak license usage for a given period. (8786, 8791)
License usage statistics retention has been extended from 600 days to 10 years. This change applies only to new installations. Existing statistics databases are not automatically migrated to the new settings. (8790)
Each page in the ThinLinc web administration interface now has a "?" button that links to the relevant section in the ThinLinc Administrator's Guide. (3964)
New configuration folder: /webaccess/oidc/. Holds settings relating to OpenID Connect authentication in ThinLinc Web Access.
New parameter: /webaccess/login/password. Controls whether password authentication is permitted or not in ThinLinc Web Access.
A complete configuration reference can be found in the ThinLinc Administrator's Guide.
ThinLinc has also been enhanced in many other ways. The complete list of corrected issues is:
3304, 3813, 3964, 4433, 4709, 4761, 4899, 5105, 5231, 5238, 5356, 5357, 5486, 5567, 5588, 5679, 5878, 5944, 6978, 6991, 7184, 8105, 8130, 8151, 8172, 8187, 8193, 8212, 8247, 8300, 8329, 8392, 8397, 8401, 8412, 8441, 8483, 8532, 8536, 8554, 8606, 8618, 8637, 8652, 8663, 8686, 8687, 8704, 8727, 8730, 8742, 8756, 8757, 8759, 8765, 8767, 8768, 8770, 8771, 8772, 8774, 8775, 8777, 8779, 8780, 8782, 8785, 8786, 8790, 8791, 8803, 8807, 8811, 8814, 8815, 8816, 8817, 8820, 8825, 8830, 8833, 8837, 8838, 8839, 8840, 8842, 8843, 8848, 8849, 8850, 8851, 8854, 8857, 8858, 8860, 8862, 8864, 8866, 8867, 8868, 8869, 8871, 8876, 8878, 8889, 8891
The ThinLinc server software will work for 3 concurrent users by default. You are allowed to use ThinLinc for free for up to 10 users; the conditions for use of the 10 free you can read at other headings in this FAQ.
To increase your limit from 3 to 10, you need to download and install a community license file from the ThinLinc Customer Portal. If you want to go for more than 10 users, you must buy user licenses from Cendio. For more information, see other headings in this FAQ.
If you don’t renew the subscription, you are not allowed to use the ThinLinc software. The customer shall then cease using the program and shall uninstall the program from any computers, servers, or other equipment. If the customer is late with the renewal with entering into a new subscription, Cendio is entitled to charge a reinstatement fee.
ThinLinc is packaged in subscriptions with a tiered pricing system. A higher number of subscriptions will give a lower price. The subscriptions can be purchased for different periods, 12, 36 and 60 month. A longer duration will give a greater price. The payment of the subscriptions is done in advance.
The default rule is that the prices are set in accordance with the number of subscriptions that are purchased at the actual call off. Deviation from this can be eventually agreed if a roll-out plan can be committed in advance.
If you have an active subscription, you are eligible for new licenses. These can be downloaded by logging in as a customer on the ThinLinc Customer Portal. Alternatively, you can email us at support@cendio.com for manual handling.
Contact Cendio support team at support@cendio.com. And refer to your ThinLinc Subscription ID in your support request.
We will set up an evaluation account that gives the permission to receive support directly from our technical team. Cendio can also provide trial licenses for more than 10 users. Please contact sales@cendio.com directly.
Cendio wants to sponsor organizations where the business aims to make the world better. This means to help people, regions etc. that really need help. Please contact us a sales@cendio.com.
Cendio offers a non-profit discount for organizations that fall under the definitions that can be found at the https://cendio.com/thinlinc/shop/non-profit-organization/. Please contact us at sales@cendio.com for pricing.
Cendio will, in good time before expiration of the ThinLinc Subscriptions Agreement, send a reminder by email. The renewal process will follow the same routines that are used in a new or additional purchase.
Other set-ups are possible for bigger deals. Contact sales@cendio.com.
Purchases can be done directly via invoice, web shop or by a reseller. Cendio is a Swedish and EU company with long experience from doing business with foreign organizations. If you have any questions or need support, please contact us at sales@cendio.com
Best functionality and performance will always be achieved by upgrading to the latest version, both on the server and client-side. A newer version on the client-side will always give a better user experience than a former version. Cendio’s ambition is to keep good compatibility and functionality between the different versions. Historically, good compatibility between versions has been 3-5 years.
A ThinLinc set-up consists of a server software, client software and user licenses.
Server software
The server software is the heart of ThinLinc installation and handles all sessions, desktop environments and generates the virtual desktop, workspace etc.
User licenses
To allow more than 10 concurrent sessions, additional user licenses need to be installed on the server. User licenses are bought from Cendio. Please note, when placing user licenses into the ThinLinc server, the counting starts from 0. This means that you need to buy and install the number of user licenses that you need, both from a technical and legal perspective.
Client software
The client software is installed on the device that is used to connect to the server and provision the virtual desktop / workspace. If using the web access client, no local installation of client software is needed, the provisioning is generated via the web browser that is installed at the server.
It's up to the licensee to decide who can connect into the server installation. The ThinLinc client software is free of charge and can be downloaded by everyone.
The licensing is per organization. There is no limitation on how the ThinLinc user licenses are distributed in the legal organization, as long as the number of consumed licenses don't exceed the number of paid licenses. It's allowed to move the user licenses, but not copy.
The license use can be seen in the status module, how to manage can be found at https://cendio.com/resources/docs/tag/tlwebadm_status.html#tlwebadm-status . ThinLinc will notify you when the limit of licenses has been reached, for detailed information see, https://cendio.com/resources/docs/tag/licensehandling.html?highlight=soft
Both the ThinLinc server and client software are free to distribute. The user licenses are connected to a purchase and are not allowed to distribute. For more detailed information, see https://cendio.com/thinlinc/docs/legal/eula
We offer technical support for a ThinLinc version for 3 years after its release date. After 3 years, Cendio can’t guarantee support on that specific version. We recommend upgrading the ThinLinc server after each bi-yearly release.
The number of user licenses that will be delivered will be in accordance with the number of subscriptions that have been acquired by the customer.
When adding user licenses into the ThinLinc server, the counting will start from zero. So if you require 200 users, you need to have 200 user licenses
You need to buy user licenses and install them in the ThinLinc server. The user licenses are received through buying ThinLinc subscriptions.
It's easy to add new users into a current ThinLinc set-up. By purchasing additional subscriptions into your agreement, so will we issue additional user licenses.
Cendio will, after receiving a valid order, distribute user licenses via email or download for the latest version after a purchase. If the purchase is a renewal and the customers have already received the latest version, no user licenses will be provided by default, updated licenses will be provided on request in this case.
It’s possible to merge existing agreements. When doing a merge, the period shall be at least 12 months.
The default rule is that the prices are set in accordance with the number of subscriptions that are purchased at the actual call off. Deviation from this can be eventually agreed if a roll-out plan can be committed in advance.
The client software packages are free of charge.
If the Agreement is not prolonged or if the fees for the agreed subscription are not paid when due, the user licenses will cease to be valid. The customer shall then cease using the program and shall uninstall the program from any computers, servers, or other equipment. The ThinLinc software will still work after the expiry date of the ThinLinc subscriptions.
Both as an individual and as an organization, it is not allowed to use the free version of ThinLinc if you have purchased user licenses.
ThinLinc is free to use for up to 10 concurrent users for both individuals and organizations (on a group basis).
ThinLinc Subscriptions give the possibility to run more than 10 concurrent users per ThinLinc installation. It also gives technical support directly from Cendio and the right to get upgrades (new versions) for ThinLinc.
ThinLinc Premium Subscription gives prioritized answers, faster response time, and direct access to our qualified technical support via telephone service.
From a technical and usability perspective, there is no difference between the free and commercial ThinLinc. The difference is from a legal and support perspective. For non-paying use, you are only allowed to use up to 10 users of the software, and the support is provided through the ThinLinc community. When you need more than 10 users, you are entitled to the commercial version of ThinLinc that is packaged in a so-called subscription. The subscription also provides you with access to high-level professional support directly from the Cendio technical team.
ThinLinc is free to use up to 10 users at the same time per individual or organization worldwide, without any obligations. The usage can be 10 installations with one user per each or one installation with 10 users. What matters is that the 10 users aren’t exceeded.
If you have an active subscription, you are eligible for new licenses. These can be downloaded by logging in as a customer on the ThinLinc Customer Portal. Alternatively, you can email us at support@cendio.com for manual handling.
Best functionality and performance will always be achieved by upgrading to the latest version, both on the server and client-side. A newer version on the client-side will always give a better user experience than a former version. Cendio’s ambition is to keep good compatibility and functionality between the different versions. Historically, good compatibility between versions has been 3-5 years.
A ThinLinc set-up consists of a server software, client software and user licenses.
Server software
The server software is the heart of ThinLinc installation and handles all sessions, desktop environments and generates the virtual desktop, workspace etc.
User licenses
To allow more than 10 concurrent sessions, additional user licenses need to be installed on the server. User licenses are bought from Cendio. Please note, when placing user licenses into the ThinLinc server, the counting starts from 0. This means that you need to buy and install the number of user licenses that you need, both from a technical and legal perspective.
Client software
The client software is installed on the device that is used to connect to the server and provision the virtual desktop / workspace. If using the web access client, no local installation of client software is needed, the provisioning is generated via the web browser that is installed at the server.
It's up to the licensee to decide who can connect into the server installation. The ThinLinc client software is free of charge and can be downloaded by everyone.
The licensing is per organization. There is no limitation on how the ThinLinc user licenses are distributed in the legal organization, as long as the number of consumed licenses don't exceed the number of paid licenses. It's allowed to move the user licenses, but not copy.
The license use can be seen in the status module, how to manage can be found at https://cendio.com/resources/docs/tag/tlwebadm_status.html#tlwebadm-status . ThinLinc will notify you when the limit of licenses has been reached, for detailed information see, https://cendio.com/resources/docs/tag/licensehandling.html?highlight=soft
Both the ThinLinc server and client software are free to distribute. The user licenses are connected to a purchase and are not allowed to distribute. For more detailed information, see https://cendio.com/thinlinc/docs/legal/eula
We offer technical support for a ThinLinc version for 3 years after its release date. After 3 years, Cendio can’t guarantee support on that specific version. We recommend upgrading the ThinLinc server after each bi-yearly release.
The ThinLinc server software will work for 3 concurrent users by default. You are allowed to use ThinLinc for free for up to 10 users; the conditions for use of the 10 free you can read at other headings in this FAQ.
To increase your limit from 3 to 10, you need to download and install a community license file from the ThinLinc Customer Portal. If you want to go for more than 10 users, you must buy user licenses from Cendio. For more information, see other headings in this FAQ.
If you don’t renew the subscription, you are not allowed to use the ThinLinc software. The customer shall then cease using the program and shall uninstall the program from any computers, servers, or other equipment. If the customer is late with the renewal with entering into a new subscription, Cendio is entitled to charge a reinstatement fee.
ThinLinc is packaged in subscriptions with a tiered pricing system. A higher number of subscriptions will give a lower price. The subscriptions can be purchased for different periods, 12, 36 and 60 month. A longer duration will give a greater price. The payment of the subscriptions is done in advance.
The default rule is that the prices are set in accordance with the number of subscriptions that are purchased at the actual call off. Deviation from this can be eventually agreed if a roll-out plan can be committed in advance.
If you have an active subscription, you are eligible for new licenses. These can be downloaded by logging in as a customer on the ThinLinc Customer Portal. Alternatively, you can email us at support@cendio.com for manual handling.
Contact Cendio support team at support@cendio.com. And refer to your ThinLinc Subscription ID in your support request.
We will set up an evaluation account that gives the permission to receive support directly from our technical team. Cendio can also provide trial licenses for more than 10 users. Please contact sales@cendio.com directly.
Cendio wants to sponsor organizations where the business aims to make the world better. This means to help people, regions etc. that really need help. Please contact us a sales@cendio.com.
Cendio offers a non-profit discount for organizations that fall under the definitions that can be found at the https://cendio.com/thinlinc/shop/non-profit-organization/. Please contact us at sales@cendio.com for pricing.
Cendio will, in good time before expiration of the ThinLinc Subscriptions Agreement, send a reminder by email. The renewal process will follow the same routines that are used in a new or additional purchase.
Other set-ups are possible for bigger deals. Contact sales@cendio.com.
Purchases can be done directly via invoice, web shop or by a reseller. Cendio is a Swedish and EU company with long experience from doing business with foreign organizations. If you have any questions or need support, please contact us at sales@cendio.com
The number of user licenses that will be delivered will be in accordance with the number of subscriptions that have been acquired by the customer.
When adding user licenses into the ThinLinc server, the counting will start from zero. So if you require 200 users, you need to have 200 user licenses
You need to buy user licenses and install them in the ThinLinc server. The user licenses are received through buying ThinLinc subscriptions.
It's easy to add new users into a current ThinLinc set-up. By purchasing additional subscriptions into your agreement, so will we issue additional user licenses.
Cendio will, after receiving a valid order, distribute user licenses via email or download for the latest version after a purchase. If the purchase is a renewal and the customers have already received the latest version, no user licenses will be provided by default, updated licenses will be provided on request in this case.
It’s possible to merge existing agreements. When doing a merge, the period shall be at least 12 months.
The default rule is that the prices are set in accordance with the number of subscriptions that are purchased at the actual call off. Deviation from this can be eventually agreed if a roll-out plan can be committed in advance.
The client software packages are free of charge.
If the Agreement is not prolonged or if the fees for the agreed subscription are not paid when due, the user licenses will cease to be valid. The customer shall then cease using the program and shall uninstall the program from any computers, servers, or other equipment. The ThinLinc software will still work after the expiry date of the ThinLinc subscriptions.
Both as an individual and as an organization, it is not allowed to use the free version of ThinLinc if you have purchased user licenses.
ThinLinc is free to use for up to 10 concurrent users for both individuals and organizations (on a group basis).
ThinLinc Subscriptions give the possibility to run more than 10 concurrent users per ThinLinc installation. It also gives technical support directly from Cendio and the right to get upgrades (new versions) for ThinLinc.
ThinLinc Premium Subscription gives prioritized answers, faster response time, and direct access to our qualified technical support via telephone service.
From a technical and usability perspective, there is no difference between the free and commercial ThinLinc. The difference is from a legal and support perspective. For non-paying use, you are only allowed to use up to 10 users of the software, and the support is provided through the ThinLinc community. When you need more than 10 users, you are entitled to the commercial version of ThinLinc that is packaged in a so-called subscription. The subscription also provides you with access to high-level professional support directly from the Cendio technical team.
ThinLinc is free to use up to 10 users at the same time per individual or organization worldwide, without any obligations. The usage can be 10 installations with one user per each or one installation with 10 users. What matters is that the 10 users aren’t exceeded.
ThinLinc is free to use up to 10 users at the same time per individual or organization worldwide, without any obligations. The usage can be 10 installations with one user per each or one installation with 10 users. What matters is that the 10 users aren’t exceeded.
