Heap Overflow Vulnerability in libXrender Affecting X Servers and Clients
CVE-2026-88807

8.9HIGH

Key Information:

Vendor

X.org

Status
Libxrender
Vendor
CVE Published:
21 September 2026

What is CVE-2026-88807?

A heap overflow vulnerability exists in libXrender versions prior to 0.9.13, specifically within the RenderQueryPictFormats function. This flaw can be exploited by malicious X servers to inject arbitrary code into connected X clients, potentially compromising their security and functionality. Users of libXrender are advised to update to the latest version to mitigate this risk.

Affected Version(s)

libXrender 0 < 0.9.13

References

https://gitlab.freedesktop.org/xorg/lib/libxrender/-/merg...
patch

CVSS V4

Score:
8.9
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Adam Bedard working with TrendAI Zero Day Initiative
Claude:claude-opus-4-6
.