CVE-2026-25920 MEDIUM

CVE-2026-25920: SumatraPDF has a heap out-of-bounds read in MOBI HuffDic decompressor

Vendor Sumatrapdfreader
Product sumatrapdf
Weakness CWE-125
Published February 9, 2026
Last update February 11, 2026
View on NVD All CVEs

CVSS base score

5.5/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

February 9, 2026 CVE published
February 11, 2026 Record updated