CVE-2025-55780

HIGH 1 PoC
MEDIUM Priority: 0.03 BB Relevance: 85/100
Published: 2025-09-23 Modified: 2026-11-05 First seen: 2026-11-05 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
artifex mupdf 1.24.0 – 1.26.7

Proof of Concept (1)

Bug Bounty Relevance

85 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction
✓ PoC available (1)

CVSS Score

7.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.45%
Raw Score 0.004490
Percentile 39.5%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00449
2026-11-12
0.00449
2026-11-10
0.00428
2026-11-09
0.00428
2026-11-08
0.00428
2026-11-07
0.00428
2026-11-06
0.00428
2026-11-05
0.00428

Intelligence Sources

nvd ref →