{"schema":"threatline.record/2","record":{"id":"CVE-2026-107737","aliases":["GHSA-8p34-f32f-7rmq"],"summary":"SumatraPDF CHM `its://` signed index causes an out-of-bounds object lookup","details":"SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. 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-2026-107737","source_modified_at":"2026-10-13T16:28:11.204Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"sumatrapdf","vendor":"sumatrapdfreader","versions":[{"status":"affected","version":"<= 3.6.1"}],"defaultStatus":null},{"source":"GitHub Advisory Database","source_url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-8p34-f32f-7rmq","source_modified_at":"2026-10-08T22:33:40Z","fetched_at":"2026-10-24T14:26:37.433577Z","package":{"ecosystem":"","name":"SumatraPDF"},"range":"3.6.1"}],"fixed_versions":[],"cvss":5.7,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.0012,"percentile":0.01705,"score_date":"2026-10-23"},"published_at":"2026-10-08T22:34:16.436Z","modified_at":"2026-10-13T16:28:11.204Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-107737","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-13T16:28:11.204Z"},{"source":"GitHub Advisory Database","url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-8p34-f32f-7rmq","fetched_at":"2026-10-24T14:26:37.433577Z","source_modified_at":"2026-10-08T22:33:40Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107737","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","GitHub Advisory Database","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-8p34-f32f-7rmq","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/sumatrapdfreader/sumatrapdf/commit/596c7e26e983549a77a3a38cae1147ab73792929","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-13T16:27:49.009801Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-13T16:28:11.204Z","content_hash":"621b551b5608c4df7ebdd3f4aa19533788aa55f9dd3ea48bc1cf14d8411ee4ad"}}