{"schema":"threatline.record/2","record":{"id":"CVE-2026-107729","aliases":["GHSA-86hq-m6hv-67h2"],"summary":"SumatraPDF: Unsigned-to-signed hdrLen validation bypass in SumatraPDF MOBI parsing causes out-of-bounds read","details":"SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, src/MobiDoc.cpp narrows the untrusted unsigned mobiHdr.hdrLen field to a signed integer for validation; values above INT_MAX become negative and bypass the upper-bound check. When the EXTH flag is set, the original unsigned value is reused as a pointer offset, causing DecodeExthHeader() to read beyond the record buffer. Opening a crafted MOBI file can reliably terminate the application with a native access violation; no code execution, information disclosure, or integrity impact has been demonstrated. No fixed version is available as of this review.","categories":["Unclassified"],"product":"sumatrapdf","vendor":"sumatrapdfreader","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107729","source_modified_at":"2026-10-09T15:46:45.488Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"sumatrapdf","vendor":"sumatrapdfreader","versions":[{"version":"<= 3.7.0.22298","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":5.5,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00146,"percentile":0.03498,"score_date":"2026-10-23"},"published_at":"2026-10-08T22:18:40.609Z","modified_at":"2026-10-09T15:46:45.488Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-107729","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-09T15:46:45.488Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107729","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-86hq-m6hv-67h2","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/sumatrapdfreader/sumatrapdf/commit/1ef900cbad02f06353b0a0747b098ca596f7c131","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-09T15:46:37.434740Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-09T15:46:45.488Z","content_hash":"5e98d0915be9f16ae2580df517e869ec314865892b3c33bc237ef5af0f968e84"}}