CVE-2026-26054
SumatraPDF: Heap out-of-bounds read in MOBI header parser.
- State
- Published
- Severity
- 6.8 Medium
- Published
- Sep 24, 2026
- Updated
- Sep 28, 2026
- Reserved
- Feb 10, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.8 Medium | 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 | GitHub_M |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
sumatrapdfsumatrapdfreader |
|
References
- https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-27p6-wrfp-pgm8
- https://github.com/sumatrapdfreader/sumatrapdf/issues/5318
- https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198
- https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel
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