CVE-2026-93421Public exploitNetwork attack vectorHinoki check available

Log forgery via unsanitized CSP report fields

Published Sep 23, 2026 · Updated Sep 23, 2026

ANSI escape-sequence injection in Mesop before 1.3.4 allows remote attackers to forge or conceal terminal log output via CSP reports. The unauthenticated /csp handler prints document-uri, blocked-uri, and violated-directive values to stdout without neutralizing control sequences. An operator must view the output in an ANSI-capable terminal, where crafted sequences can clear, reposition, hide, or replace displayed monitoring text.

CVSS severity5.3
Medium
EPSS probability0.40%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

ANSI escape-sequence injection in Mesop before 1.3.4 allows remote attackers to forge or conceal terminal log output via CSP reports. The unauthenticated /csp handler prints document-uri, blocked-uri, and violated-directive values to stdout without neutralizing control sequences. An operator must view the output in an ANSI-capable terminal, where crafted sequences can clear, reposition, hide, or replace displayed monitoring text.

The record

CVE
CVE-2026-93421
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
mesop-dev
Product
Mesop
Classifications
CWE-150, CWE-117, T1562.006
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 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=< 1.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

mesop-dev · Mesopversion=< 1.3.4

Published CVSS scores

5.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-150Improper Neutralization of Escape, Meta, or Control Sequences
CWE-117Improper Output Neutralization for Logs
T1562.006Indicator Blocking

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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