Quick answers
- Is CVE-2026-93515 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-93515 being exploited in the wild.
- How severe is CVE-2026-93515?
- Informational severity, published 28 October 2026.
- Which products and versions are affected?
- X.Org X Wayland before 24.1.14; X.Org X Server before 21.1.25.
- Is there a fix for CVE-2026-93515?
- Yes: fixed in X Server 21.1.25; X Wayland 24.1.14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-93515 attacked?
- It is attacked with local access, in a hosted service.
- Am I affected by CVE-2026-93515?
- Check whether you run X.Org X Wayland or X.Org X Server 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 21.1.25; X Wayland 24.1.14
Technical details
A use-after-free write occurs in present_clear_window_notifies() when cross-window Present notifies are used. When a notify-target window is destroyed while an untriggered wait_fence keeps a vblank alive, dangling pointers remain in the window notify list; subsequent vblank teardown calls present_free_window_notify() which writes through these pointers. The vulnerability requires local X protocol access.
Affected products
- X.org X Server before 21.1.25
- X.org X Wayland before 24.1.14
Timeline
- 2026-10-28: disclosed
- 2026-08-26: patched: Commit 1b6955c3 by Peter Hutterer