Medium Denial of service exploit reference

CVE-2025-71382 — MuPDF < 1.27.0-rc1 Stack Exhaustion DoS via EPUB CSS Rendering

MuPDF before 1.27.0-rc1 contains an uncontrolled recursion vulnerability in the EPUB CSS rendering engine that allows remote attackers to cause a denial of service by supplying a maliciously crafted EPUB file with deeply nested HTML elements and inline CSS styles. The function value_from_inheritable_property() in css-apply.c recurses through the CSS property inheritance chain without a depth limit, exhausting the process stack and causing a crash in any application using MuPDF for EPUB rendering.

Published Jun 23, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.6% (30-day exploitation probability)+7
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.58%

ahead of 47% of scored CVEs · Oct 15, 2026

Affects

Artifex

Mupdf and 1 more

CVSS base

6.5

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented mitigation — bugs.ghostscript.com (NIST National Vulnerability Database)
Documented patch — github.com (NIST National Vulnerability Database)
Documented patch — www.vulncheck.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Artifex Mupdf, Artifex Software MuPDF).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Artifex	Mupdf	< 1.27.0	Vulnerable	NIST National Vulnerability Database
Artifex Software	MuPDF	< 1.27.0-rc1	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.1	CVSS 4.0	High	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
7.1	CVSS 4.0	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
6.5	CVSS 3.1	Medium	2.8	3.6	disclosure@vulncheck.com via NIST National Vulnerability Database
6.5	CVSS 3.1	Medium	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-674 · Uncontrolled Recursion

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.58%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Track CPU/memory spikes and availability drops correlated with request patterns.

web/proxy/WAF logsnetwork IDS/IPSresource metrics

Timeline

What happened to this CVE, newest first.

2026
Affected products added · artifexsoftware/mupdf
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 6.5
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 23, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

github.com/ArtifexSoftware/mupdf/commit/70b71ab22e6de4d4c44cd301c88231f623a4e94e
Patch, patch, NIST National Vulnerability Database
www.vulncheck.com/advisories/mupdf-rc1-stack-exhaustion-dos-via-epub-css-rendering
Patch, Third Party Advisory, third-party-advisory, NIST National Vulnerability Database
bugs.ghostscript.com/show_bug.cgi
Exploit, Issue Tracking, Mitigation, technical-description, exploit, NIST National Vulnerability Database
github.com/ArtifexSoftware/mupdf/releases/tag/1.27.0-rc1
Release Notes, release-notes, NIST National Vulnerability Database

Elsewhere on this site

Artifex
every CVE for this vendor

Denial of service
same class

CWE-674
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-92413 Artifex MuPDF PDF Xref Loading pdf-stream.c pdf_open_filter null pointer dereference 29d
Medium CVE-2026-7233 Artifex MuPDF CFF Index subset-cff.c fz_subset_cff_for_gids out-of-bounds Apr 28, 2026
Low CVE-2026-40505 MuPDF < 1.27 mutool ANSI Injection via Metadata Apr 15, 2026
High CVE-2025-15569 Artifex MuPDF win_main.c get_system_dpi uncontrolled search path Feb 10, 2026
High CVE-2026-25556 MuPDF 1.23.0 through 1.27.0 Barcode Decoding Double Free Feb 6, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-71382 is "MuPDF < 1.27.0-rc1 Stack Exhaustion DoS via EPUB CSS Rendering", rated Medium. It affects Mupdf (Artifex); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.58% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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