{"id":"CVE-2026-25961","summary":"SumatraPDF Update MITM -\u003e Arbitrary Code Execution","details":"SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification (INTERNET_FLAG_IGNORE_CERT_CN_INVALID) and executes installers without signature checks. A network attacker with any valid TLS certificate (e.g., Let's Encrypt) can intercept the update check request, inject a malicious installer URL, and achieve arbitrary code execution.","aliases":["GHSA-xpm2-rr5m-x96q"],"modified":"2026-08-12T03:51:24.344129384Z","published":"2026-02-09T21:34:05.203Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-295","CWE-494"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25961.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25961.json"},{"type":"ADVISORY","url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-xpm2-rr5m-x96q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25961"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sumatrapdfreader/sumatrapdf","events":[{"introduced":"bd84decaa54254d42dd3eda35399c5dd1b3ab57e"},{"last_affected":"646d1feddcc80b3b51072c5b27a1446487904175"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:sumatrapdfreader:sumatrapdf:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"3.5.0"},{"last_affected":"3.5.2"},{"introduced":"3.5"}]}}],"versions":["3.5.2rel","3.5.1rel","3.5rel"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25961.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}