Out-of-bounds Read in Sumatrapdfreader Sumatrapdf
CVE-2026-107738
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.
Vulnerability class: Buffer Overflow
Published · last modified .
EPSS exploit prediction
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Affected products
- Sumatrapdfreader Sumatrapdf — versions <= 3.6.1