CVE-2026-34085

EUVD-2026-15934
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.9 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
mitreCNA
5.9 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
fontconfig_projectfontconfig
𝑥
< 2.17.1
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/b9bec06d73340f1b5727302d13ac3df307b7febc
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/merge_requests/446
https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/481