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.
Published: 2026-09-23
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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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
History

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'}

Subscriptions

No data.

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

No data.

cve-icon NVD

Status : Received

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

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

Link: CVE-2026-93421

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-117

    Improper Output Neutralization for Logs

  • CWE-150

    Improper Neutralization of Escape, Meta, or Control Sequences