Integer overflow in CHMLib
Priority MEDIUM 58CWE-190Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00183 7th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
No affected products listed by the sources yet.
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-48172
- 2026-10-03 Alias added: GHSA-rpc6-w47v-qqr6
References
Other 4
- https://drive.google.com/file/d/1XpulFyCGlq7Szzg5RsH-eRwZ6OyuSozl/view?usp=sharing
- https://drive.google.com/file/d/1wq51px42eoJz2VQ1Qu9ObPVQVom9T9H_/view?usp=sharing
- https://github.com/jedwing/CHMLib/blob/2bef8d063ec7d88a8de6fd9f0513ea42ac0fa21f/src/chm_lib.c#L1386
- https://github.com/sumatrapdfreader/sumatrapdf/commit/08179946a745cf1605e4b9670942ec1a6e1f4c5d
More CHMLib vulnerabilities
- TI-2007-00604 chmlib before 0.39 allows user-assisted remote attackers to execute arbitrary code via a… CVSS 2.0HIGH 9.3
Sources
- CVE-2025-48172 · CVE Program
- CVE-2025-48172 · NVD
- FIRST EPSS
- GHSA-rpc6-w47v-qqr6 · GitHub Advisory Database · CC BY 4.0
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