CVE-2026-25920
SumatraPDF has a heap out-of-bounds read in MOBI HuffDic decompressor
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.
INFO
Published Date :
Feb. 9, 2026, 10:16 p.m.
Last Modified :
Feb. 20, 2026, 8:22 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update SumatraPDF to version 3.6 or later.
- Avoid opening crafted MOBI files.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-25920.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-25920 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-25920
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-25920 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-25920 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 20, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:sumatrapdfreader:sumatrapdf:*:*:*:*:*:*:*:* versions up to (including) 3.5.2 Added Reference Type GitHub, Inc.: https://github.com/sumatrapdfreader/sumatrapdf/blob/916392f94bc34e24f3c3286893ac6d7fa1e1c428/src/MobiDoc.cpp Types: Product Added Reference Type GitHub, Inc.: https://github.com/sumatrapdfreader/sumatrapdf/commit/12b6887e9dfff874fe8749bab1bdc53d4ff075b3 Types: Product Added Reference Type GitHub, Inc.: https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-5mwx-65x7-cffp Types: Exploit, Vendor Advisory -
CVE Modified by [email protected]
Feb. 11, 2026
Action Type Old Value New Value Changed Description SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, tA 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. 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. -
New CVE Received by [email protected]
Feb. 09, 2026
Action Type Old Value New Value Added Description SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, tA 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. Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-125 Added Reference https://github.com/sumatrapdfreader/sumatrapdf/blob/916392f94bc34e24f3c3286893ac6d7fa1e1c428/src/MobiDoc.cpp Added Reference https://github.com/sumatrapdfreader/sumatrapdf/commit/12b6887e9dfff874fe8749bab1bdc53d4ff075b3 Added Reference https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-5mwx-65x7-cffp