CVE-2026-34352: TigerVNC x0vncserver incorrect permissions in shared memory image

CVE-2026-34352 · Severity: high · CVSS 8.5 · Published 2026-03-26

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.

Technologies: Tigervnc. Vendors: Tigervnc.

Quick answers

Is CVE-2026-34352 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34352 being exploited in the wild.
How severe is CVE-2026-34352?
High severity, with a CVSS score of 8.5, published 26 March 2026.
Which products and versions are affected?
Tigervnc before 1.16.2.
Is there a fix for CVE-2026-34352?
A patch was published on 2026-03-26: Fix committed to TigerVNC repository and version 1.16.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34352 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-34352?
Check whether you run Tigervnc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

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

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