Executive brief
TigerVNC is a suite of remote desktop software used to view and control graphical desktops over a network. A security flaw in the x0vncserver component allows other local users on the same computer to view or modify the screen contents of an active session. This could lead to the exposure of sensitive information or allow an attacker to disrupt the user's session by causing the application to crash.
Technical details
A vulnerability exists in the x0vncserver component of TigerVNC due to the use of insecure permissions (0777) when creating SysV shared memory segments for the framebuffer backing store in Image.cxx. This allows any local user on the same host to attach to the shared memory segments used for desktop capture. An attacker can exploit this to monitor screen contents (confidentiality), modify the framebuffer (integrity), or cause a denial-of-service by crashing the server. The issue is fixed in version 1.16.2 by restricting the shared memory permissions to 0600.
Affected products
- TigerVNC TigerVNC before 1.16.2
Timeline
- 2026-03-23: disclosed: Issue reported on GitHub
- 2026-03-26: advisory: CVE-2026-34352 published
- 2026-03-26: patched: Fix committed to TigerVNC repository and version 1.16.2 released
References
- https://github.com/TigerVNC/tigervnc/commit/0b5cab169d847789efa54459a87659d3fd484393
- https://github.com/TigerVNC/tigervnc/issues/2079
- https://groups.google.com/g/tigervnc-announce/c/anHL9WLshLI
- https://sourceforge.net/projects/tigervnc/files/stable/1.16.2
- https://www.openwall.com/lists/oss-security/2026/03/26/7