CVE-2026-40505

Terminal spoofing via unquoted embedded font names

Published Apr 16, 2026 · Updated Apr 16, 2026

ANSI injection in MuPDF before 1.27 allows attackers to manipulate terminal output when a user inspects a crafted PDF with mutool info. source/tools/pdfinfo.c prints an embedded font name with the raw %s formatter, allowing control bytes in that name to reach the terminal; the patch replaces it with quoted %q formatting. Exploitation requires a local user to run mutool info on an attacker-supplied file; the reported consequence is display clearing and forged terminal text.

CVSS severity4.8
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

ANSI injection in MuPDF before 1.27 allows attackers to manipulate terminal output when a user inspects a crafted PDF with mutool info. source/tools/pdfinfo.c prints an embedded font name with the raw %s formatter, allowing control bytes in that name to reach the terminal; the patch replaces it with quoted %q formatting. Exploitation requires a local user to run mutool info on an attacker-supplied file; the reported consequence is display clearing and forged terminal text.

The record

CVE
CVE-2026-40505
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
Artifex Software, Inc.
Product
MuPDF
Classifications
CWE-150, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0f17d789fe8c29b41e47663be82514aaca3a4dfb

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Artifex Software, Inc. · MuPDFversion=0 <0f17d789fe8c29b41e47663be82514aaca3a4dfb

Published CVSS scores

3.3VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
4.8VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-150Improper Neutralization of Escape, Meta, or Control Sequences
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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