CVE-2026-107737

MEDIUMCVSS 5.7/10

Last modified

CVE-2026-107737 is a medium-severity vulnerability rated 5.7/10 on the CVSS scale. SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows.

Description

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. No fixed version is available as of this review.

Metrics

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-107737?
SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. No fixed version is available as of this review.
How severe is CVE-2026-107737?
CVE-2026-107737 has a CVSS score of 5.7/10 (MEDIUM severity).
How do I fix CVE-2026-107737?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST