ThinLinc 4.15.0 Release Notes


Cendio are proud to present ThinLinc 4.15.0, with more than 140 enhancements and fixes. The most prominent changes are:

  • Managing a ThinLinc cluster from the command line has been made easier in various ways, primarily by a first version of a new tool called "tlctl". All ThinLinc command-line tools have also gotten man pages, and it's now easier to use the tools via sudo.

  • Cendio and ThinLinc have refreshed their branding, and as part of that, all of ThinLinc has gotten a graphical update. The change is primarily visual, so users will be able to find most things in the places they are used to.

  • Various minor security fixes and improvements in the ThinLinc server. Users are encouraged to upgrade at a convenient time.

  • The EULA has been updated to allow the ThinLinc server to be more easily distributed. This means that it is no longer necessary for third-party vendors to instruct their users to download the ThinLinc server package directly from Cendio's website.

ThinLinc works on most modern Linux distributions and is supported on any platform that fulfills our documented requirements.

Changes in this Release

In the list below, the bug number is given in parentheses. For more information, visit


  • The appearance and layout of all parts of ThinLinc have been refreshed with a new graphical design. (4889, 7902, 7904, 7905, 7906, 7907, 7908, 7909, 7926, 7960, 7976, 7997, 8179, 8180)


  • The ThinLinc server now consists of a single RPM or deb package instead of several smaller packages. (4885)

  • It is now permitted to distribute the ThinLinc server, provided all terms of the EULA are followed. (8155)

  • Fixed an issue where unauthenticated connections could result in incorrect notifications about shadowers being disconnected. This could happen even if no shadower was connected to begin with. These notifications would appear as popups in user sessions (7830).

  • Patched multiple security vulnerabilities where a malicious application could cause the X server to crash or execute arbitrary code. [CVE-2021-4008, CVE-2021-4009, CVE-2021-4010, CVE-2021-4011, CVE-2022-2319, CVE-2022-2320, CVE-2022-3550, CVE-2022-3551, CVE-2022-4283, CVE-2022-46340, CVE-2022-46341, CVE-2022-46343, CVE-2022-46344, CVE-2023-0494, CVE-2023-1393] (7971, 8085, 8138, 8160)

  • The ThinLinc session will now allow access to all applications running as the user who started the session, not just applications that have access to the Xauthority file. This makes ThinLinc behave more like most major distributions and solves compatibility issues with restricted environments such as snap applications. (7788)

  • All license files must now be issued for the same version to avoid the system calculating an incorrect number of valid licenses. The license files and the ThinLinc software can still have different versions, as long as the software doesn't have a higher version than the license files. (4937)

  • Administration commands are more easily accessible by automatically adding /opt/thinlinc/sbin to PATH for all users. As a side effect, regular users will see ThinLinc commands that require superuser privileges when using tab completion. (7672)

  • Fixed an issue where ThinLinc Setup would crash when upgrading from ThinLinc 4.9.0 or older (7865)

  • The vsmagent service will no longer crash if the content of /etc/ssh/sshd_config is in an unexpected encoding. (7847)

  • Fixed an issue where sessions could fail to start if another X server was using a display number within the range configured for ThinLinc. (7930)

  • Setting a background image during session startup no longer requires the tool "xsri" and will now work correctly on most distributions. This image can be set through the parameter /sessionstart/background_image. The scaling of the image has also changed to better match how background images are scaled by desktop environments. (3054, 7906, 7949, 7952)

  • Fixed an issue where the session would continue starting even if the user clicked "Quit" in the profile chooser. (7917)

Native Client

  • SHA-1 is no longer supported for SSH host keys or SSH public key authentication. This means that the ThinLinc server must be running OpenSSH 7.2 or later, or other key types than RSA must be used (7535, 7961)

  • The Linux 32-bit x86 ThinLinc client is no longer available. Users are advised to switch to the 64-bit client. (7962)

  • The ThinLinc client can now connect to Red Hat Enterprise Linux 9 servers without reconfiguring the SSH server to avoid a bug in the server's RSA host key handling. (7933)

  • The IGEL and ThinStation packages are now 64-bit for improved compatibility and performance. (6185, 7363)

  • Fixed an issue where the ThinLinc client would only show a black screen when entering full-screen mode on macOS 13. (8046)

  • Fixed an issue where the ThinLinc client would lose keyboard focus when leaving full-screen mode on macOS 13. (8049)

ThinLinc Web Access

  • Fixed various issues where Web Access could be tricked into showing a page controlled by an attacker by having a user click on a link controlled by the attacker. (7986, 7851)

Smart Card Support

  • Fixed a regression in ThinLinc 4.14.0 where some smart card applications would not work correctly under ThinLinc because of the missing symbol "pcsc_stringify_error". (7946)


  • The ThinLinc server now comes with a new command-line tool for administration, "tlctl". It can list sessions, terminate sessions, and display load balancing information. (3707, 425, 7833, 7834)

  • When upgrading the ThinLinc server packages, the ThinLinc services are now automatically stopped for the full duration of the upgrade. This means that users cannot create new sessions or reconnect to running sessions during this period. The services are started again once ThinLinc Setup finishes. (7163)

  • ThinLinc's Web Administration has an overhauled interface where configuration details are now displayed in popups, instead of directly inside the tables. (8075)

  • The agent load information and the list of sessions in ThinLinc's Web Administration have been revamped to present the information more clearly. (8077, 8083)

  • Fixed an issue where tl-config didn't print the folder names when used without the recursive flag. (7780)

  • Fixed an issue where ThinLinc Web Administration could crash if the lpstat command was not available. (8063)


  • The ThinLinc Administrator's Guide is now installed with the ThinLinc server to make sure the correct documentation is always available. Once the server is installed, it can be found under the path /opt/thinlinc/share/doc/thinlinc-server/html. (1161)

  • man pages are now installed for all ThinLinc server commands. (7049)

  • Fixed an issue where it was not possible to search for some words in the ThinLinc Administrator's Guide. (7853)

Corrected Issues

ThinLinc has also been enhanced in many other ways. The complete list of corrected issues is:

 425, 1161, 3054, 3707, 3854, 3950, 4382, 4839, 4878, 4885, 4889,
4937, 5042, 5064, 5084, 5204, 5267, 5506, 5900, 6010, 6185, 7049,
7123, 7163, 7195, 7363, 7460, 7535, 7541, 7623, 7624, 7672, 7780,
7788, 7790, 7810, 7827, 7828, 7830, 7833, 7834, 7835, 7841, 7842,
7847, 7851, 7852, 7853, 7855, 7857, 7859, 7860, 7862, 7865, 7868,
7870, 7878, 7882, 7883, 7886, 7902, 7904, 7905, 7906, 7907, 7908,
7909, 7911, 7915, 7917, 7918, 7926, 7930, 7932, 7933, 7935, 7936,
7939, 7946, 7947, 7949, 7950, 7951, 7952, 7960, 7961, 7962, 7971,
7976, 7986, 7989, 7990, 7995, 7997, 7998, 8000, 8011, 8013, 8022,
8023, 8026, 8027, 8046, 8049, 8056, 8057, 8062, 8063, 8064, 8067,
8071, 8073, 8075, 8076, 8077, 8080, 8083, 8085, 8087, 8095, 8097,
8101, 8102, 8106, 8110, 8111, 8121, 8122, 8124, 8138, 8141, 8146,
8149, 8155, 8157, 8158, 8160, 8166, 8169, 8175, 8176, 8177, 8179,
Android is a registered trademark of Google, Inc.
ARM is a registered trademark of ARM Limited.
Debian is a registered trademark of Software in the Public Interest, Inc.
Dell is a registered trademark of Dell Inc.
eDirectory is a registered trademark of NetIQ Corporation.
eLux is a registered trademark of UniCon Software GmbH.
Fedora is a registered trademark of Red Hat, Inc.
Firefox is a registered trademark of The Mozilla Foundation.
Google Earth is a registered trademark of Google Inc.
HP is a registered trademark of Hewlett-Packard Company.
IGEL is a registered trademark of IGEL Technology GmbH
Java is a registered trademark of Oracle Corporation.
Linux is a registered trademark of Linus Torvalds.
Linux Mint is a trademark of Linux Mark Institute.
NetWare and Novell are registered trademarks of Novell, Inc.
OpenGL is a registered trademark of Silicon Graphics, Inc.
Oracle is a registered trademark of Oracle Corporation.
macOS and OS X are registered trademarks of Apple Computer, Inc.
PostScript is a registered trademark of Adobe Systems Inc.
Red Hat is a registered trademark of Red Hat, Inc.
SUSE is a registered trademark of SUSE LLC.
ThinLinc is a registered trademark of Cendio AB.
Ubuntu is a registered trademark of Canonical Ltd.
Unicode is a registered trademark of Unicode, Inc.
UNIX is a registered trademark of The Open Group.
Windows is a registered trademark of Microsoft, Inc.
VMware is a registered trademark of VMware, Inc.
Wyse is a registered trademark of Wyse Technology Inc.

Frequently Asked Questions

  • 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.

  • Every valid ThinLinc Subscription Agreement has a specific ID. Contact Cendio at and refer to your ID, and we will issue new user licenses for you.

  • Contact Cendio support team at 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 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

  • Cendio offers a non-profit discount for organizations that fall under the definitions that can be found at the Please contact us at 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

  • 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


  • 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 sessions to connect access to the server software, user licenses need to be added into the server software. User licenses are bought from Cendio. Please note, when placing user licenses into the ThinLinc server, the counting starts from 0, not 10. In concrete, this means that you need to buy and install the number of user licenses that you need.

    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 . ThinLinc will notify you when the limit of licenses has been reached, for detailed information see,

  • 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

  • A specific version of ThinLinc is supported 3 years from release date. After 3 years, Cendio can’t guarantee support.

  • 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. The user licenses are perpetual.

  • 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 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 delivered by default, updated licenses will be delivered 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.

  • The ThinLinc license is perpetual and 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 valid 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.

  • The free version of ThinLinc is limited to 10 concurrent users and is supported via the ThinLinc Community. The commercial version of ThinLinc is packaged in a so-called subscription and can be scaled for more than 10 users. The subscriptions also give the right to get professional support in ThinLinc 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.

How can we help you?