Integer overflow in Sumatrapdfreader Sumatrapdf

CVE-2026-107730

SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, LitParseHeader() in src/LitDoc.cpp computes the attacker-controlled hdrLen + nPieces * 16 section offset using signed 32-bit arithmetic without validating the complete result. When the component values make that aggregate calculation overflow to a negative value, pointer construction reaches an invalid read in LitU32(), causing deterministic application termination. The supplied evidence does not demonstrate code execution, information disclosure, arbitrary read, or integrity impact. No fixed version is available as of this review.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-107730?
CVE-2026-107730 is a medium-severity vulnerability in Sumatrapdfreader Sumatrapdf, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2026-10-08.
How severe is CVE-2026-107730?
Medium severity. CVSS v3 base score is 5.5 out of 10.