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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34085.json",
"cna_assigner": "mitre",
"cwe_ids": [
"CWE-193"
]
}