Heap-based buffer overflow in p11-kit - CVE-2026-18938

Vulnerability identifier: #VU146999

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-18938

CWE-ID: CWE-122

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a heap-based buffer overflow in the p11-kit RPC parsing process when processing nested attributes in specially crafted messages. A local user can send specially crafted messages to cause a denial of service.

The vulnerability is only exploitable on 32-bit systems.

p11-kit
openEuler
Anolis OS
Fedora
p11-kit
p11-kit-debuginfo
p11-kit-debugsource
p11-kit-devel
p11-kit-help
p11-kit-server
p11-kit-trust
p11-kit-doc

Install security update from vendor's website.

p11-kit - update to 0.26.5
p11-kit - update to 0.25.0-3
p11-kit-debuginfo - update to 0.25.0-3
p11-kit-debugsource - update to 0.25.0-3
p11-kit-devel - update to 0.25.0-3
p11-kit-help - update to 0.25.0-3
p11-kit-server - update to 0.25.0-3
p11-kit-trust - update to 0.25.0-3
p11-kit - update to 0.25.0-3
p11-kit-devel - update to 0.25.0-3
p11-kit-server - update to 0.25.0-3
p11-kit-trust - update to 0.25.0-3
p11-kit-doc - update to 0.25.0-3
p11-kit - addressed in versions 0.26.5-1.fc43, 0.26.5-1.fc44

• https://github.com/advisories/GHSA-6x8p-h5fj-5ppr
• https://github.com/p11-glue/p11-kit/releases/tag/0.26.5

• Denial of service in p11-kit
• Fedora 44 update for p11-kit
• Fedora 43 update for p11-kit
• openEuler update for p11-kit
• Anolis OS update for p11-kit