CVE-2026-107738
SumatraPDF is a multi-format reader for Windows
- Risk score
- 41/100
- CVSS
- 6.8 v4.0
- Exploit chance (30 days)
- 0.1%
- Published
- 8 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, ChmFile::GetCharZ() narrows file-controlled unsigned string offsets from /#WINDOWS and /#IVB to signed integers without a lower-bound check. An offset that becomes negative can make the function read before the /#STRINGS buffer, causing determinist…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 6.8 medium
References
Original description
SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, ChmFile::GetCharZ() narrows file-controlled unsigned string offsets from /#WINDOWS and /#IVB to signed integers without a lower-bound check. An offset that becomes negative can make the function read before the /#STRINGS buffer, causing deterministic application termination. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.
Last activity 8 Oct 2026. Patch Forecast updates every hour.