Home/CVE/fontconfig before 2.17.1 has an off-by-one error in allocation during sfnt capability handling, leading to a one-byte ou
CVE

CVE-2026-34085

fontconfig before 2.17.1 has an off-by-one error in allocation during sfnt capability handling, leading to a one-byte ou

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.

MEDIUM · CVSS 5.9 EPSS 0.00017
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-193Off-by-one Error
▤

Affected Products & Versions

1
fontconfig project fontconfigall versions
▣

Scoring & Timeline

5.9
MEDIUM · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD25 Mar 2026 · 05:17 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

2
msrcCVE-2026-34085
rhsaRHSA-2026:13722Moderate
🔗

References & Sources

3
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/b9bec06d73340f1b5727302d13ac3df307b7febcPatch
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/merge_requests/446Patch
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/481Issue Tracking
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