CVE Intelligence
Medium Memory corruption exploit reference

CVE-2026-112036 — Artifex MuPDF Signature Locking pdf-xref.c free_char_list double free

A vulnerability was detected in Artifex MuPDF up to 1.28.5. This impacts the function free_char_list of the file source/pdf/pdf-xref.c of the component Signature Locking. Performing a manipulation results in double free. The attack may be initiated remotely. The exploit is now public and may be used. The patch is named 3984925b660afb8a781ddf504021e91be1bc671e. To fix this issue, it is recommended to deploy a patch.

Published Oct 18, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

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 0.3% (30-day exploitation probability)+4
  • Technical severity (medium)+3
  • CISA SSVC: exploitation "poc"+5
  • Automatable exploitation (SSVC)+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
0.34%
ahead of 26% of scored CVEs · Oct 21, 2026
Affects
Artifex
Mupdf
CVSS base
4.3
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
Proof of concept
none · proof-of-concept · active
Automatable
Yes
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.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Artifex Mupdf).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  5. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Artifex Mupdf version 1.28.0version 1.28.1version 1.28.2version 1.28.3version 1.28.4version 1.28.5 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
Low

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 4.0 Medium — — VulDB via CVE Program (cve.org) e CISA ADP
2.1 CVSS 4.0 Low — — cna@vuldb.com via NIST National Vulnerability Database
4.3 CVSS 3.1 Medium 2.8 1.4 cna@vuldb.com via NIST National Vulnerability Database
4.3 CVSS 3.1 Medium — — VulDB via CVE Program (cve.org) e CISA ADP
4.3 CVSS 3.0 Medium — — VulDB via CVE Program (cve.org) e CISA ADP
5.0 CVSS 2.0 Medium 10.0 2.9 cna@vuldb.com via NIST National Vulnerability Database
5.0 CVSS 2.0 Medium — — VulDB 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:L (score shown at the top: cna@vuldb.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 19, 2026 → Oct 21, 2026 · 3 reading(s) · max 0.34%

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).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 19, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · Received → Deferred
    Oct 19, 2026 · NIST National Vulnerability Database
  • Affected products added · artifex/mupdf
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 18, 2026
  • CVSS changed · 4.3
    Oct 18, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 18, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 18, 2026 · Alertas do Telegram
  • CVE published
    Oct 18, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 18, 2026 – Oct 18, 2026
  • 1× Official description updated · Oct 18, 2026 – Oct 18, 2026

References

8 on the record

Elsewhere on this site

Artifex
every CVE for this vendor
Memory corruption
same class
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-92413 Artifex MuPDF PDF Xref Loading pdf-stream.c pdf_open_filter null pointer dereference Sep 16, 2026
  • CVE-2025-71382 MuPDF < 1.27.0-rc1 Stack Exhaustion DoS via EPUB CSS Rendering Jun 23, 2026
  • CVE-2026-7233 Artifex MuPDF CFF Index subset-cff.c fz_subset_cff_for_gids out-of-bounds Apr 28, 2026
  • CVE-2026-40505 MuPDF < 1.27 mutool ANSI Injection via Metadata Apr 15, 2026
  • CVE-2025-15569 Artifex MuPDF win_main.c get_system_dpi uncontrolled search path Feb 10, 2026
  • 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 fixed version, patch or mitigation documented.
  • 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-2026-112036 is "Artifex MuPDF Signature Locking pdf-xref.c free_char_list double free", 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 4.3 describes technical severity. EPSS 0.34% 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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