Home/CVE/SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in
CVE

CVE-2026-25920

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in

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.

MEDIUM · CVSS 5.5 EPSS 0.00027
Schedule remediation
  • Public exploit or PoC is available
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-125Out-of-bounds Read
▤

Affected Products & Versions

1
sumatrapdfreader sumatrapdf<= 3.5.2
⚠

Public Exploits & PoCs

1
pocgithub.com · GHSA-5mwx-65x7-cffpgithub.com
▣

Scoring & Timeline

5.5
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD09 Feb 2026 · 10:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/sumatrapdfreader/sumatrapdf/blob/916392f94bc34e24f3c3286893ac6d7fa1e1c428/src/MobiDoc.cppProduct
https://github.com/sumatrapdfreader/sumatrapdf/commit/12b6887e9dfff874fe8749bab1bdc53d4ff075b3Product
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