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. 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.

Published: 2025-09-23 Last update: 2025-10-08 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-55780 is rated Low Risk (35.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-55780

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-10-25 0.05% 0.05% +0.00%
2 2025-10-09 0.05% 0.05% -0.00%
3 2025-09-29 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-55780

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-55780

OS Trackers for CVE-2025-55780

vendor priority summary link
alpine — CVE-2025-55780: 1 source package rows (mupdf); 14 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 14. https://security.alpinelinux.org/vuln/CVE-2025-55780
debian not yet assigned CVE-2025-55780 not yet assigned priority: Debian including 1 source packages (mupdf), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2025-55780
ubuntu medium CVE-2025-55780 medium priority: Ubuntu including 1 source packages (mupdf), 8 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, upstream, xenial): needs-triage 7, ignored 1. https://ubuntu.com/security/CVE-2025-55780

Affected software / configurations for CVE-2025-55780

Vendor Product Version Raw CPE
artifex mupdf >= 1.24.0, < 1.26.7 cpe:2.3:a:artifex:mupdf:*:*:*:*:*:*:*:*

References for CVE-2025-55780

cvelogic Threat Intelligence