---
id: CVE-2026-93421
title: >-
  Mesop is a Python-based UI framework that allows users to build web
  applications
summary: >-
  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…
severity: medium
cvss: 5.3
cvssVector: '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'
cwe:
  - CWE-117
  - CWE-150
vendor: mesop-dev
product: mesop
affected:
  - mesop < 1.3.4
patched:
  - mesop 1.3.4
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:22.503'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93421'
references:
  - url: >-
      https://github.com/mesop-dev/mesop/commit/f38c42a1d3eba246941ef8d7f645072d53c58785
    label: security-advisories@github.com
  - url: 'https://github.com/mesop-dev/mesop/pull/1397'
    label: security-advisories@github.com
  - url: 'https://github.com/mesop-dev/mesop/releases/tag/v1.3.4'
    label: security-advisories@github.com
  - url: 'https://github.com/mesop-dev/mesop/security/advisories/GHSA-g7f6-rxc4-qhph'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-g7f6-rxc4-qhph'
  - url: 'https://github.com/mesop-dev/mesop'
tags:
  - nvd
  - cve.org
  - ghsa
  - pip
  - osv
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T19:25:37.624256Z'
cvssSource: cna
aliases:
  - GHSA-g7f6-rxc4-qhph
ecosystem: pip
ingestedAt: '2026-09-23T19:31:04.473Z'
epss: 0.00404
epssPercentile: 0.31921
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-93421)

Affected packages:

- `mesop <= 1.3.3`

Patched in:

- `mesop 1.3.4`

Source: https://github.com/advisories/GHSA-g7f6-rxc4-qhph