TemplateSandbox does not check read permissions for the page being previewed (CVE-2026-100240) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-100240

TemplateSandbox does not check read permissions for the page being previewed

Answer in brief

CVE-2026-100240 records a Unknown severity vulnerability in TemplateSandbox does not check read permissions for the page being previewed. The current sources do not mark it as known exploited. The current feed maps Wikimedia Foundation/Mediawiki - TemplateSandbox 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 29, 2026Updated Sep 29, 2026Source checked Sep 29, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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 - TemplateSandbox Extension (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Wikimedia Foundation/Mediawiki - TemplateSandbox Extensiongeneric	>=* <1.46.1 1.45.5 1.43.10	1.46.1, 1.45.5, 1.43.10, 1.46.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for Wikimedia Foundation/Mediawiki - TemplateSandbox Extension.
Review the reported fix. Update Wikimedia Foundation/Mediawiki - TemplateSandbox Extension to 1.46.1, 1.45.5, 1.43.10 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Upstream source description

Missing Authorization vulnerability in Wikimedia Foundation Mediawiki - TemplateSandbox Extension allows Accessing Functionality Not Properly Constrained by ACLs. This issue affects Mediawiki - TemplateSandbox Extension: from * before 1.46.1, 1.45.5, 1.43.10.

Quoted source text, attributed separately from HOL analysis.