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.
Affected products
artifex: mupdf
References3
- bugs.ghostscript.com/show_bug.cgi?id=708720 Issue TrackingThird Party Advisory
- cgit.ghostscript.com/cgi-bin/cgit.cgi/mupdf.git/commit/?id=bdd5… Permissions Required
- github.com/ISH2YU/CVE-2025-55780/tree/main Third Party Advisory
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 37 · as of 8 November 2026
- CWE
- CWE-476
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