Description
SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in SumatraPDF's MOBI HuffDic decompressor. The bounds check in AddCdicData() only validates half the range that DecodeOne() actually accesses. Opening a crafted .mobi file can read nearly (1 << codeLength) bytes beyond the CDIC dictionary buffer, leading to a crash.
Metrics
CVSS 3.1 5.5/10
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| sumatrapdfreader | sumatrapdf | <= 3.5.2 |
References
- https://github.com/sumatrapdfreader/sumatrapdf/blob/916392f94bc34e24f3c3286893ac6d7fa1e1c428/src/MobiDoc.cppProduct
- https://github.com/sumatrapdfreader/sumatrapdf/commit/12b6887e9dfff874fe8749bab1bdc53d4ff075b3Product
- https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-5mwx-65x7-cffpExploit, Vendor Advisory
Timeline
- Published
- Feb 9, 2026
- Last modified
- Jun 17, 2026
- NVD status
- Analyzed