Vulnerability 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.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976ab
- https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x
- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x
FAQ
What is CVE-2026-52766?
CVE-2026-52766 is a vulnerability with a CVSS score of 9.1 (CRITICAL). 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 wik...
How severe is CVE-2026-52766?
CVE-2026-52766 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-52766?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.