Screen disclosure and manipulation via world-readable shared memory
Published Mar 26, 2026 · Updated Mar 26, 2026
Incorrect permissions in TigerVNC x0vncserver before 1.16.2 allow local users to read or alter captured screen data or crash the server. ShmImage::Init creates the active X11 framebuffer's SysV shared-memory segment with mode 0777, permitting unrelated accounts to attach and modify it. The vulnerable path requires x0vncserver to capture an X display; timed modifications can interrupt service by crashing the process.
Summary
What happened
Incorrect permissions in TigerVNC x0vncserver before 1.16.2 allow local users to read or alter captured screen data or crash the server. ShmImage::Init creates the active X11 framebuffer's SysV shared-memory segment with mode 0777, permitting unrelated accounts to attach and modify it. The vulnerable path requires x0vncserver to capture an X display; timed modifications can interrupt service by crashing the process.
The record
- CVE
- CVE-2026-34352
- Published
- Mar 26, 2026
- Updated
- Mar 26, 2026
- Vendor
- TigerVNC
- Product
- TigerVNC
- Classifications
- CWE-732, T1005
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 26, 2026CVE publishedPublication date reported by the CVE source.
- Mar 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.16.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- TigerVNC issue 2079 runtime reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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