CVE-2026-26054
Description
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 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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198
- https://github.com/sumatrapdfreader/sumatrapdf/issues/5318
- https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel
- https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-27p6-wrfp-pgm8
CWEs
CWE-125
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.