{"id":"CVE-2026-26054","title":"SumatraPDF is a multi-format reader for Windows","summary":"SumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without …","severity":"medium","cvss":6.8,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-125"],"vendor":"sumatrapdfreader","product":"sumatrapdf","affected":["sumatrapdf < 3.6"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T17:17:04.673","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-26054","references":[{"url":"https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198","label":"security-advisories@github.com"},{"url":"https://github.com/sumatrapdfreader/sumatrapdf/issues/5318","label":"security-advisories@github.com"},{"url":"https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel","label":"security-advisories@github.com"},{"url":"https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-27p6-wrfp-pgm8","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-09-24T17:48:30.383Z","slug":"CVE-2026-26054","body":"## Overview\n\nSumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without receiving the actual remaining buffer length. A malformed MOBI file can use an attacker-controlled header length to bypass optional-field early returns and cause the decoder to read beyond a short heap buffer. Opening the crafted document can crash SumatraPDF. This issue is fixed in version 3.6.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":37,"depthScoreParts":{"impact":37.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}