Quick answers
- Is CVE-2026-93520 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-93520 being exploited in the wild.
- How severe is CVE-2026-93520?
- High severity, with a CVSS score of 7.8, published 28 October 2026.
- Which products and versions are affected?
- X.Org X Server before 2.1.25; X.Org XWayland before 24.1.14.
- Is there a fix for CVE-2026-93520?
- Yes: fixed in X server 2.1.25, XWayland 24.1.14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-93520 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-93520?
- Check whether you run X.Org X Server or X.Org XWayland 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.
How to fix
- Fixed in: X server 2.1.25, XWayland 24.1.14
Technical details
The vulnerability is a heap buffer overflow caused by inconsistent size calculations between XkbAllocNames() and XkbChangeKeycodeRange(). XkbAllocNames() allocates names->keys based on max_key_code+1, but after a prior fix, XkbChangeKeycodeRange() assumes MAP_LENGTH (256) and memsets beyond the actual allocation when max_key_code is smaller. An authenticated X client can trigger this by loading a keymap with small max_key_code then issuing a SetMap request to extend maxKeyCode to 255, causing out-of-bounds memory writes.
Affected products
- X.org X server before 2.1.25
- X.org XWayland before 24.1.14
Timeline
- 2026-10-28: disclosed: CVE published on NVD
- 2026-08-26: patched: Fix committed to xserver repository