{"id":"CVE-2026-55518","aliases":["GHSA-8fq9-273g-6mrg"],"url":"https://o3.security/vulnerability/CVE-2026-55518","summary":"Avo: Missing Authorization in Avo Association Attach Endpoint Allows Unauthorized Relationship Manipulation and Privilege Escalation","details":"Avo is a framework to create admin panels for Ruby on Rails apps. Prior to 3.32.1 and 4.0.0.beta.51, Avo's association attach workflow checks attach_<association>? in the UI and GET /resources/:resource/:id/:related/new path, but the actual write endpoint, POST /resources/:resource/:id/:related, does not run the same authorization check before mutating the association through Avo::AssociationsController#create. An authenticated low-privileged Avo user can bypass hidden or disabled attach controls and directly attach related records to a parent record by sending a crafted POST request, which can lead to privilege escalation and cross-tenant data exposure where associations represent authorization-bearing relationships. This issue is fixed in versions 3.32.1 and 4.0.0.beta.51.","published":"2026-07-17T20:51:19.056Z","modified":"2026-08-12T03:51:24.630166831Z","cvss":{"score":9.6,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"},"epss":{"score":0.00331,"percentile":0.26083,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"RubyGems","name":"avo","fixedVersion":"3.32.1"},{"ecosystem":"RubyGems","name":"avo","fixedVersion":"4.0.0.beta.51"}],"fix":{"url":"https://github.com/avo-hq/avo/commit/995928e586fd1788dd496bd51c4dbe4a79cb2b9c","label":"avo-hq/avo@995928e"},"references":[{"type":"WEB","url":"https://github.com/avo-hq/avo/releases/tag/v3.32.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55518.json"},{"type":"ADVISORY","url":"https://github.com/avo-hq/avo/security/advisories/GHSA-8fq9-273g-6mrg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55518"},{"type":"FIX","url":"https://github.com/avo-hq/avo/commit/995928e586fd1788dd496bd51c4dbe4a79cb2b9c"},{"type":"FIX","url":"https://github.com/avo-hq/avo/pull/4568"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:24.630166831Z"}}