CVE-2026-107731: CWE-125: Out-of-bounds Read in sumatrapdfreader sumatrapdf
Description
CVE-2026-107731 is an out-of-bounds read vulnerability in SumatraPDF version 3.7.0.22298 and earlier. It involves multiple range-validation issues in the src/LitDoc.cpp file, allowing crafted LIT files to cause invalid pointer reads and deterministic application termination. No broader impact beyond application termination is reported. No fixed version is currently available.
CVSS v3.1
Score 5.5medium
Affected software
sumatrapdfreader
sumatrapdf
pkg:github/sumatrapdfreader/sumatrapdfRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
SumatraPDF 3.7.0.22298 and earlier contain four independently reachable range-validation flaws in src/LitDoc.cpp. These flaws allow file-controlled offsets and sizes to overflow, narrow to negative values, or wrap before incomplete bounds checks, affecting variables such as contentOffset, directory expression dirOff64 + dirLen64, decoded-section offset + size, and secondary-header range handling. Opening a specially crafted LIT file triggering these conditions can cause invalid pointer reads leading to deterministic application termination. No further impact beyond denial of service is documented. No patch or fix is available as of the advisory.
Potential Impact
The vulnerability can cause SumatraPDF to terminate unexpectedly when opening a crafted LIT file, resulting in a denial of service condition. There is no evidence of confidentiality or integrity impact. No known exploits are reported in the wild.
Mitigation Recommendations
No fixed version is currently available. Users should avoid opening untrusted or suspicious LIT files to mitigate risk until a patch is released.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-08T17:21:52.976Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac81a5e2cdf04f6563e4cfc
Added to database: 10/08/2026, 22:34:06 UTC
Last enriched: 10/08/2026, 22:48:54 UTC
Last updated: 10/08/2026, 22:49:04 UTC
Views: 8
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