# CVE-2026-109088: libXtst RECORD EnableContext Reply Endless Loop

CVE-2026-109088 is fixed in libxtst on 1 platform by DEBIAN-CVE-2026-109088 (version 2:1.2.6-1), released November 1, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-109088
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0027
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 27, 2026
- Weakness: Loop with Unreachable Exit Condition ('Infinite Loop')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109088

## Description

A malicious X server could send malformed  RECORD EnableContext reolies that can cause a X client using the parse_reply_call_callback function in libXtst before 1.2.6 to enter a endless loop.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libxtst Debian 14 | 2:1.2.6-1 | [DEBIAN-CVE-2026-109088](https://patchblox.com/security/data/fix/linux/debian-cve-2026-109088.md) | Nov 1, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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