CVE-2026-107730

Deferred Deferred - Pending Action

Heap Overflow in SumatraPDF via LitParseHeader

Publication date: 2026-10-08

Last updated on: 2026-10-08

Assigner: GitHub, Inc.

Description

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.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-08

Last Modified

2026-10-08

Generated

2026-10-09

AI Q&A

2026-10-09

EPSS Evaluated

N/A

NVD

CVE-2026-107730

Affected Vendors & Products

Vendor	Product	Version / Range
sumatrapdfreader	sumatrapdf	<= 3.7.0.22298

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

Executive Summary

SumatraPDF 3.7.0.22298 has a flaw in LitParseHeader() where it calculates a section offset using signed 32-bit arithmetic without checking for overflow. If the calculation results in a negative value due to overflow, it causes an invalid read in LitU32(), leading to the application crashing deterministically.

Detection Guidance

This vulnerability is specific to SumatraPDF 3.7.0.22298 and involves a signed integer overflow in LitParseHeader(). Detection requires checking the installed version of SumatraPDF. If version 3.7.0.22298 is found, the system is vulnerable.

Impact Analysis

This vulnerability causes the SumatraPDF application to crash when processing certain files. It does not allow code execution, information disclosure, or data tampering, but repeated crashes could disrupt document viewing workflows.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR, HIPAA, or similar regulations as it does not lead to data breaches, unauthorized access, or integrity violations. However, application crashes could affect availability, which may be a secondary consideration for operational compliance.

Mitigation Strategies

Since no fixed version is available, the immediate step is to uninstall or avoid using SumatraPDF version 3.7.0.22298. Monitor the official SumatraPDF website or repository for updates and apply patches once released.

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