Stored i18n XSS in WikiLambda's VisualEditor integration (CVE-2026-100383) | HOL Guard CVE

Medium · CVSS 4.8CVE-2026-100383

Stored i18n XSS in WikiLambda's VisualEditor integration

Answer in brief

CVE-2026-100383 records a Medium severity (CVSS 4.8) vulnerability in Stored i18n XSS in WikiLambda's VisualEditor integration. The current sources do not mark it as known exploited. The current feed maps Wikimedia Foundation/Mediawiki - WikiLambda Extension (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

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

Published Sep 25, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 4.8. 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 Wikimedia Foundation/Mediawiki - WikiLambda Extension (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Wikimedia Foundation/Mediawiki - WikiLambda Extensiongeneric	1.47.0-alpha	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Wikimedia Foundation/Mediawiki - WikiLambda Extension.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - WikiLambda Extension allows Cross-Site Scripting (XSS). This issue affects Mediawiki - WikiLambda Extension: 1.47.0-alpha. The issue has been remediated on the `master` branch.

Quoted source text, attributed separately from HOL analysis.