X Client Vulnerability in libXtst Affecting FreeDesktop.org
CVE-2026-109088

6.5MEDIUM

Key Information:

Vendor

X.org

Status
Libxtst
Vendor
CVE Published:
27 October 2026

What is CVE-2026-109088?

A vulnerability exists in libXtst where a malicious X server can send malformed RECORD EnableContext replies. This can lead to X clients that utilize the parse_reply_call_callback function entering an endless loop, potentially causing a denial of service. Users of libXtst versions prior to 1.2.6 are advised to update to a patched version to mitigate the risk.

Affected Version(s)

libXtst 0 < 1.2.6

References

https://gitlab.freedesktop.org/xorg/lib/libxtst/-/merge_r...
patch

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Kaya Emre Arikan
.