{"id":"CVE-2026-52766","aliases":["GHSA-6x7x-gcmf-7r8x"],"url":"https://o3.security/vulnerability/CVE-2026-52766","summary":"YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action","details":"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.","published":"2026-09-04T23:40:12.087Z","modified":"2026-09-06T03:46:00.811624798Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"},"epss":{"score":0.00331,"percentile":0.25869,"asOf":"2026-09-06"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"yeswiki/yeswiki","fixedVersion":"4.6.6"}],"fix":{"url":"https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef","label":"YesWiki/yeswiki@ed5b548"},"references":[{"type":"WEB","url":"https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52766.json"},{"type":"ADVISORY","url":"https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52766"},{"type":"FIX","url":"https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-06T03:46:00.811624798Z"}}