{"id":"CVE-2026-53609","aliases":["GHSA-6h5j-32cf-4253"],"url":"https://o3.security/vulnerability/CVE-2026-53609","summary":"Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass","details":"ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, `apos.util.set()` traverses dot-notation paths without sanitizing `__proto__`, allowing an authenticated editor to write arbitrary values to `Object.prototype` via the `$pullAll` patch operator. A confirmed gadget in `publicApiCheck()` causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.","published":"2026-06-12T20:59:25.486Z","modified":"2026-08-12T03:51:30.115866152Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"apostrophe","fixedVersion":"4.31.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53609.json"},{"type":"ADVISORY","url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-6h5j-32cf-4253"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53609"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:30.115866152Z"}}