CVE-2025-48172 Details
Description
CHMLib through 2bef8d0, as used in SumatraPDF and other products, has a chm_lib.c _chm_decompress_block integer overflow. There is a resultant heap-based buffer overflow in _chm_fetch_bytes.
A heap-based buffer overflow vulnerability has been identified in CHMLib, a library used for handling CHM files, which is embedded in SumatraPDF versions 3.4.3 and later. The issue arises from an integer overflow in the '_chm_decompress_block' function, leading to incorrect memory allocation. This flaw allows a crafted CHM file to trigger a write past the bounds of a heap allocation, potentially overwriting memory and causing corruption.
Users can update to the latest version of SumatraPDF, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 4, 2025CISA-ADP
Assessed Jul 8, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://drive.google.com/file/d/1XpulFyCGlq7Szzg5RsH-eRwZ6OyuSozl/view?usp=sharing | CISA-ADP | Technical AnalysisPartial Content |
| https://drive.google.com/file/d/1wq51px42eoJz2VQ1Qu9ObPVQVom9T9H_/view?usp=sharing | [email protected] | ExploitPermission Required |
| https://drive.google.com/file/d/1XpulFyCGlq7Szzg5RsH-eRwZ6OyuSozl/view?usp=sharing | [email protected] | Technical AnalysisPartial Content |
| https://github.com/jedwing/CHMLib/blob/2bef8d063ec7d88a8de6fd9f0513ea42ac0fa21f/src/chm_lib.c#L1386 | [email protected] | Source Code |
| https://github.com/sumatrapdfreader/sumatrapdf/commit/08179946a745cf1605e4b9670942ec1a6e1f4c5d | [email protected] | Source CodeVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-190 | Integer Overflow or Wraparound | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| CHMLib | All versions |
CPE
Remediation
| |
| SumatraPDF | All versions |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2025 | CVE Modified | CISA-ADP |
| Jul 4, 2025 | New CVE Received | [email protected] |