Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.4, the unauthenticated /__csp__ endpoint passes attacker-controlled document-uri, blocked-uri, and violated-directive values to the csp_report handler in mesop/server/static_file_serving.py, which prints them to standard output without neutralizing terminal control sequences. When an operator views the resulting logs in an ANSI-capable terminal, injected ANSI or VT100 sequences can clear or reposition the display, hide text, or present forged messages, reducing the integrity of monitoring and incident-response output. This issue is fixed in version 1.3.4.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
mesop-dev mesop affected
Version Status Constraints
< 1.3.4 affected —

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Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-g7f6-rxc4-qhph Mesop: Unauthenticated ANSI Escape Sequence Injection in CSP Reporting Endpoint
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/mesop-dev/mesop/commit/f38c42a1d3eba246941ef8d7f645072d53c58785 cve-icon cve-icon
https://github.com/mesop-dev/mesop/pull/1397 cve-icon cve-icon
https://github.com/mesop-dev/mesop/releases/tag/v1.3.4 cve-icon cve-icon
https://github.com/mesop-dev/mesop/security/advisories/GHSA-g7f6-rxc4-qhph cve-icon cve-icon
History

Wed, 23 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 23 Sep 2026 19:15:00 +0000

Type Values Removed Values Added
Description Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.4, the unauthenticated /__csp__ endpoint passes attacker-controlled document-uri, blocked-uri, and violated-directive values to the csp_report handler in mesop/server/static_file_serving.py, which prints them to standard output without neutralizing terminal control sequences. When an operator views the resulting logs in an ANSI-capable terminal, injected ANSI or VT100 sequences can clear or reposition the display, hide text, or present forged messages, reducing the integrity of monitoring and incident-response output. This issue is fixed in version 1.3.4.
Title Mesop: Unauthenticated ANSI Escape Sequence Injection in CSP Reporting Endpoint
Weaknesses CWE-117
CWE-150
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-23T19:41:34.966Z

Reserved: 2026-09-17T20:57:18.984Z

Link: CVE-2026-93421

cve-icon Vulnrichment

Updated: 2026-09-23T19:25:43.446Z

cve-icon NVD

Status : Received

Published: 2026-09-23T19:19:45.140

Modified: 2026-09-23T20:17:22.503

Link: CVE-2026-93421

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses