---
id: CVE-2026-111059
title: >-
  Mercury: Stored / DOM Cross-Site Scripting (XSS): mr.Markdown renders
  untrusted content as raw, unsanitized HTML
summary: >-
  Mercury is a Python framework for sharing Jupyter notebooks as web
  applications and dashboards. From 3.0.0 until 3.2.11, mr.Markdown converts
  attacker-controlled Markdown to HTML without sanitizing raw HTML before
  assigning it to an ipyw…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
  - CWE-116
vendor: mljar
product: mercury
affected:
  - 'mercury >= 3.0.0, < 3.2.11'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-20T15:10:08.190617Z'
published: '2026-10-19'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T16:11:40.067Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111059'
references:
  - url: 'https://github.com/mljar/mercury/security/advisories/GHSA-2658-85cv-9wwq'
    label: 'https://github.com/mljar/mercury/security/advisories/GHSA-2658-85cv-9wwq'
  - url: >-
      https://github.com/mljar/mercury/commit/c798a85924e6614c6fea7afe5a560e4554a1d09b
    label: >-
      https://github.com/mljar/mercury/commit/c798a85924e6614c6fea7afe5a560e4554a1d09b
  - url: 'https://github.com/mljar/mercury/releases/tag/v3.2.11'
    label: 'https://github.com/mljar/mercury/releases/tag/v3.2.11'
  - url: 'https://github.com/advisories/GHSA-2658-85cv-9wwq'
tags:
  - cve.org
  - ghsa
  - pip
epss: 0.00284
epssPercentile: 0.21014
aliases:
  - GHSA-2658-85cv-9wwq
ecosystem: pip
patched:
  - mercury 3.2.11
ingestedAt: '2026-10-19T17:33:42.443Z'
---

## Overview

Mercury is a Python framework for sharing Jupyter notebooks as web applications and dashboards. From 3.0.0 until 3.2.11, mr.Markdown converts attacker-controlled Markdown to HTML without sanitizing raw HTML before assigning it to an ipywidgets.HTML sink. Event-handler attributes and other active HTML can therefore reach the DOM and execute when another user views the application. This issue is fixed in version 3.2.11.

## Affected

- `mercury >= 3.0.0, < 3.2.11`

## Remediation

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

## Package advisory (CVE-2026-111059)

Affected packages:

- `mercury >= 3.0.0, < 3.2.11`

Patched in:

- `mercury 3.2.11`

Source: https://github.com/advisories/GHSA-2658-85cv-9wwq