CVE-2026-34085

fontconfig: Fontconfig: Security flaw allows arbitrary code execution or system crash

Published Mar 25, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
fontconfig before 2.17.1 has an off-by-one error in allocation during sfnt capability handling, leading to a one-byte out-of-bounds write, and potentially a crash or code execution. This is in FcFontCapabilities in fcfreetype.c.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:fontconfig_project:fontconfig:2.17.0:*:*:*:*:*:*:*
Type Values Removed Values Added
CPEs cpe:2.3:a:fontconfig_project:fontconfig:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Off-by-One Vulnerability in Fontconfig May Enable Code Execution fontconfig: Fontconfig: Security flaw allows arbitrary code execution or system crash
References
Metrics threat_severity

None

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Fontconfig Project
Fontconfig Project fontconfig
Vendors & Products Fontconfig Project
Fontconfig Project fontconfig
Type Values Removed Values Added
Title Off-by-One Vulnerability in Fontconfig May Enable Code Execution
Type Values Removed Values Added
Description fontconfig before 2.17.1 has an off-by-one error in allocation during sfnt capability handling, leading to a one-byte out-of-bounds write, and potentially a crash or code execution. This is in FcFontCapabilities in fcfreetype.c.
Weaknesses CWE-193
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Apr 2, 2026, 5:50 PM
Reserved
Mar 25, 2026, 4:54 PM
Status
Analyzed
Published
Mar 25, 2026, 5:17 PM
Modified
Jun 17, 2026, 10:38 AM
Severity
Moderate
Public date
Mar 25, 2026, 4:54 PM