{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-53609: Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-53609","status":"final","version":"1","initial_release_date":"2026-06-12T20:59:25.486Z","current_release_date":"2026-06-12T20:59:25.486Z","revision_history":[{"date":"2026-06-12T20:59:25.486Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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 `$pullAll` patch operator. A confirmed gadget in `publicApiCheck()` causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-53609 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-53609"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-53609"},{"category":"external","summary":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-6h5j-32cf-4253","url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-6h5j-32cf-4253"}]},"product_tree":{"branches":[{"category":"vendor","name":"apostrophecms","branches":[{"category":"product_name","name":"apostrophe","branches":[{"category":"product_version","name":"<= 4.30.0","product":{"name":"apostrophecms apostrophe <= 4.30.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:apostrophecms:apostrophe:\\<\\=_4.30.0:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-53609","title":"Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass","notes":[{"category":"description","text":"ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, `apos.util.set()` traverses dot-notation paths without sanitizing `__proto__`, allowing an authenticated editor to write arbitrary values to `Object.prototype` via the `$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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L","baseScore":9.1,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}