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NVD / CVE Program· CNA VulnCheck

CVE-2026-40505: MuPDF < 1.27 mutool ANSI Injection via Metadata

Noroxi assessment

Priority: Monitor (action score 19/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No special conditions are required; it is repeatable.
  • Fixed version: Artifex Software Inc. MuPDF 1.27.0.

Low priority for now. Upgrade to Artifex Software Inc. MuPDF 1.27.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

MuPDF before 1.27 contains an ANSI injection vulnerability in mutool that allows attackers to inject arbitrary ANSI escape sequences through crafted PDF metadata fields. Attackers can embed malicious ANSI escape codes in PDF metadata that are passed unsanitized to terminal output when running mutool info, enabling them to manipulate terminal display for social engineering attacks such as presenting fake prompts or spoofed commands.

MediumCVSS 4.8 · v4.0—No exploit Fix available
Published
Apr 16, 2026
Updated
Nov 8, 2026
EPSS
0.1% · 5th percentile

Report tools

JSON

Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
4.8
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-40505

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
artifexmupdf

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • artifex mupdfbefore 1.27.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • Artifex Software Inc. MuPDF

    • 0f17d789fe8c29b41e47663be82514aaca3a4dfbaffected
    • before 1.27.0affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12mupdffrom 0—
Debian:14mupdfbefore 1.27.0+ds1-51.27.0+ds1-5

Same product

artifex: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-7321Usage of an uninitialized variable in the function fz_load_jpeg in Artifex MuPDF 1.14 can result in a heap overflow vulnerability that allow
    40Plan
  • CVE-2021-3407A flaw was found in mupdf 1.18.0.
    37Monitor
  • CVE-2017-5991An issue was discovered in Artifex MuPDF before 1912de5f08e90af1d9d0a9791f58ba3afdb9d465.
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-25556Feb 6, 2026 · MuPDF 1.23.0 through 1.27.0 Barcode Decoding Double Free
    23Monitor
  • ← EarlierCVE-2025-15569Feb 10, 2026 · Artifex MuPDF win_main.c get_system_dpi uncontrolled search path
    29Monitor
  • Later →CVE-2026-7233Apr 28, 2026 · Artifex MuPDF CFF Index subset-cff.c fz_subset_cff_for_gids out-of-bounds
    7Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Artifex Software Inc. MuPDF1.27.0Vendor (CNA)
debian:mupdf1.27.0+ds1-5 · Debian:14Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
P
Scope
X

Weakness class (CWE)

CWE-150 · Improper Neutralization of Escape, Meta, or Control Sequences

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records