CVE-2025-55780: artifex mupdf NULL Pointer Dereference
Vulnerability summary
CVE-2025-55780 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in artifex mupdf. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 23-09-2025PublishedVulnerability first disclosed.
- 25-09-2025Last modifiedVulnerability information updated.
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 metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
0.00 pp
From 0.43% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Artifex1 product
- mupdf≥ 1.24.0, < 1.26.7
Debian1 product
- mupdfAll versions (No fix recorded) | < 1.27.0+ds1-2
Ubuntu1 product
- mupdfAll versions (No fix recorded)
3 vendors · 3 products
References
6 links- github.com/ISH2YU/CVE-2025-55780/tree/mainThird Party Advisory
