High severity · published Sep 23, 2025
CVE-2025-55780
A null pointer dereference occurs in the function break_word_for_overflow_wrap() in MuPDF 1.26.4 when rendering a malformed EPUB document
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
A null pointer dereference occurs in the function break_word_for_overflow_wrap() in MuPDF 1.26.4 when rendering a malformed EPUB document. Specifically, the function calls fz_html_split_flow() to split a FLOW_WORD node, but does not check if node->next is valid before accessing node->next->overflow_wrap, resulting in a crash if the split fails or returns a partial node chain.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MU
Mupdf · Artifex
1.24.0 before 1.26.7 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55780
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-55780
Issue Tracking
https://bugs.ghostscript.com/show_bug.cgi?id=708720
Permissions Required
https://cgit.ghostscript.com/cgi-bin/cgit.cgi/mupdf.git/commit/?id=bdd5d241748807378a78a622388e0312332513c5
Third Party Advisory
https://github.com/ISH2YU/CVE-2025-55780/tree/main
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