CVE-2025-55780: Null Pointer Dereference

Published Sep 23, 2025
·
Updated

A null pointer dereference occurs in the function breakwordforoverflowwrap() in MuPDF 1.26.4 when rendering a malformed EPUB document. Specifically, the function calls fzhtmlsplitflow() to split a FLOWWORD node, but does not check if node->next is valid before accessing node->next->overflowwrap, resulting in a crash if the split fails or returns a partial node chain.

Affected Software

2 affected components
Artifex Mupdf
Artifex Mupdf>=1.24.0<1.26.7

Event History

Sep 23, 2025
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Data Sourced
via NVD·06:15 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2025-55780?

CVE-2025-55780 is considered a critical severity vulnerability due to the potential for application crashes when processing malformed EPUB documents.

2

How do I fix CVE-2025-55780?

To fix CVE-2025-55780, update to the latest version of MuPDF where the null pointer dereference issue has been resolved.

3

What software is impacted by CVE-2025-55780?

CVE-2025-55780 affects versions of MuPDF, specifically version 1.26.4 and earlier when rendering malformed EPUB documents.

4

What type of vulnerability is CVE-2025-55780?

CVE-2025-55780 is a null pointer dereference vulnerability that can lead to application crashes.

5

Do I need to take immediate action on CVE-2025-55780?

Yes, immediate action is recommended to mitigate the risks associated with CVE-2025-55780 by updating affected software.

Contact

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CVE-2025-55780 - Null Pointer Dereference - SecAlerts