YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action (CVE-2026-52766) | HOL Guard CVE

Critical severityCVE-2026-52766GHSA-6X7X-GCMF-7R8X

YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action

Answer in brief

CVE-2026-52766 records a Critical severity vulnerability in YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action. The current sources do not mark it as known exploited. The current feed maps yeswiki/yeswiki (composer), YesWiki/yeswiki (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 4, 2026Updated Sep 4, 2026Source checked Sep 5, 2026First seen by HOL Jul 10, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Critical
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
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 yeswiki/yeswiki (composer), YesWiki/yeswiki (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
yeswiki/yeswikicomposer	<4.6.6	4.6.6
YesWiki/yeswikigeneric	< 4.6.6	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for yeswiki/yeswiki, YesWiki/yeswiki.
Review the reported fix. Update yeswiki/yeswiki to 4.6.6 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 10, 2026

Sources and claim methodology

Upstream source description

YesWiki is a wiki system written in PHP. Prior to version 4.6.6, the {{erasespamedcomments}} wiki action (actions/EraseSpamedCommentsAction.php) accepts a suppr[] array from POST and deletes every wiki page whose tag appears in that array, with no authorization check anywhere in the action body or in the page-deletion path it invokes. Combined with YesWiki's allow-by-default action ACL model, any user who has page write access, which is the default for everyone (default_write_acl='*') on a fresh install can permanently delete arbitrary wiki pages, including the front page, admin pages, and pages owned by other users. This issue has been patched in version 4.6.6.

Quoted source text, attributed separately from HOL analysis.