Vulnerability · Published Sep 4, 2026 · Assigned by GitHub_M

CVE-2026-52766YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action

Critical 9.1

In plain English

A critical-severity incorrect default permissions in yeswiki from YesWiki. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.1Critical

Exploit odds (30 days)0.6%top 52.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	yeswiki/yeswiki	4.6.6	GHSA-6x7x-gcmf-7r8x

Affected products (as reported)

Vendor	Product	Versions
YesWiki	yeswiki	< 4.6.6

Weakness: CWE-276, CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

References

https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x x_refsource_CONFIRM
https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef x_refsource_MISC
https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6 x_refsource_MISC