Medium · CVSS 6.1CVE-2026-111059GHSA-2658-85CV-9WWQ

Mercury: Stored / DOM Cross-Site Scripting (XSS): mr.Markdown renders untrusted content as raw, unsanitized HTMLCVE-2026-111059

Answer in brief

CVE-2026-111059 records a Medium severity (CVSS 6.1) vulnerability in Mercury: Stored / DOM Cross-Site Scripting (XSS): mr.Markdown renders untrusted content as raw, unsanitized HTML. The current sources do not mark it as known exploited. The current feed maps mljar/mercury (generic), mercury (pip), mercury (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 19, 2026Updated Oct 19, 2026Source checked Oct 19, 2026First seen by HOL Oct 19, 2026Material review Oct 19, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.1
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps mljar/mercury (generic), mercury (pip), mercury (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
mljar/mercurygeneric	>=3.0.0 <3.2.11	3.2.11
mercurypip	>=3.0.0,<3.2.11	3.2.11
mercurypypi	>=3.0.0 <3.2.11	3.2.11

Recommended response

Check inventory. Check lockfiles and deployed manifests for mljar/mercury, mercury, mercury.
Review the reported fix. Update mljar/mercury to 3.2.11; mercury to 3.2.11; mercury to 3.2.11 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 19, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.