{"id":"EEF-CVE-2026-82685","summary":"Confirmation token accepted on any record in AshAuthentication","details":"## Summary\n\nAuthorization Bypass Through User-Controlled Key vulnerability in team-alembic AshAuthentication allows an authenticated attacker to overwrite and confirm another user's email address, and so take over that account. A confirmation token issued to one user is accepted on any other user's record.\n\n`AshAuthentication.AddOn.Confirmation.ConfirmChange` verifies the token's signature and its `act` claim, then applies the changes stored against that token to whichever record the changeset targets, never comparing the `sub` claim against `changeset.data`. An attacker who registers an account and changes their own email replays the resulting token against a victim's record id, writing in their own address with `force_change_attributes/2` and stamping `confirmed_at`, after which an ordinary password reset yields the account. The library's own confirmation flow is unaffected, because `AshAuthentication.AddOn.Confirmation.Actions.confirm/3` resolves `sub` to a user and targets that record.\n\nThis issue affects ash_authentication: from 0.5.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.","aliases":["CVE-2026-82685","GHSA-g636-26vf-2w63"],"modified":"2026-09-17T13:26:04.340611555Z","published":"2026-09-17T13:08:56.491Z","database_specific":{"cpe_ids":["cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-639"],"capec_ids":["CAPEC-21"]},"references":[{"type":"ADVISORY","url":"https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-g636-26vf-2w63"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-82685.html"},{"type":"WEB","url":"https://github.com/team-alembic/ash_authentication/commit/1d4bb00617aecae85c33f2ff5bc7e094c6449a6e"},{"type":"FIX","url":"https://github.com/team-alembic/ash_authentication/commit/d7c15c21d39c009206e010cd67e2d86370fe7a28"},{"type":"FIX","url":"https://github.com/team-alembic/ash_authentication/commit/2a2396af131ab67e2f445b805fecce8e6ca86c0e"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_authentication"}],"affected":[{"package":{"name":"ash_authentication","ecosystem":"Hex","purl":"pkg:hex/ash_authentication"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.5.0"},{"fixed":"4.15.0"}]},{"type":"SEMVER","events":[{"introduced":"5.0.0-rc.0"},{"fixed":"5.0.0-rc.14"}]}],"versions":["3.0.3","3.1.0","3.10.0","3.10.1","3.10.2","3.10.3","3.10.4","3.10.5","3.10.6","3.10.7","3.10.8","3.11.0","3.11.1","3.11.10","3.11.11","3.11.12","3.11.13","3.11.14","3.11.15","3.11.16","3.11.2","3.11.3","3.11.4","3.11.5","3.11.6","3.11.7","3.11.8","3.11.9","3.12.0","3.12.1","3.12.2","3.12.3","3.12.4","3.2.0","3.2.1","3.2.2","3.3.0","3.3.1","3.5.0","3.5.1","3.5.2","3.5.3","3.6.0","3.6.1","3.7.0","3.7.1","3.7.2","3.7.3","3.7.4","3.7.5","3.7.6","3.7.8","3.7.9","3.8.0","3.9.0","3.9.1","3.9.2","3.9.3","3.9.4","3.9.5","3.9.6","4.0.0","4.0.0-rc.0","4.0.0-rc.1","4.0.0-rc.2","4.0.0-rc.3","4.0.0-rc.5","4.0.0-rc.6","4.0.1","4.0.2","4.0.3","4.0.4","4.1.0","4.10.0","4.11.0","4.12.0","4.13.0","4.13.1","4.13.2","4.13.3","4.13.4","4.13.5","4.13.6","4.13.7","4.14.0","4.14.1","4.14.2","4.2.0","4.2.1","4.2.2","4.2.3","4.2.4","4.2.5","4.2.6","4.2.7","4.3.0","4.3.1","4.3.10","4.3.11","4.3.12","4.3.2","4.3.3","4.3.4","4.3.5","4.3.6","4.3.7","4.3.8","4.3.9","4.4.0","4.4.1","4.4.2","4.4.3","4.4.4","4.4.5","4.4.6","4.4.7","4.4.8","4.4.9","4.5.0","4.5.1","4.5.2","4.5.3","4.5.4","4.5.5","4.5.6","4.6.0","4.6.1","4.6.2","4.6.3","4.6.4","4.7.0","4.7.1","4.7.2","4.7.3","4.7.4","4.7.5","4.7.6","4.8.0","4.8.1","4.8.2","4.8.3","4.8.5","4.8.6","4.8.7","4.9.0","4.9.1","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7","4.9.8","4.9.9","5.0.0-rc.0","5.0.0-rc.1","5.0.0-rc.10","5.0.0-rc.11","5.0.0-rc.12","5.0.0-rc.13","5.0.0-rc.2","5.0.0-rc.3","5.0.0-rc.4","5.0.0-rc.5","5.0.0-rc.6","5.0.0-rc.7","5.0.0-rc.8","5.0.0-rc.9"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-82685.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/team-alembic/ash_authentication","events":[{"introduced":"1d4bb00617aecae85c33f2ff5bc7e094c6449a6e"},{"fixed":"d7c15c21d39c009206e010cd67e2d86370fe7a28"},{"fixed":"2a2396af131ab67e2f445b805fecce8e6ca86c0e"}]}],"versions":["v4.14.2","v5.0.0-rc.13","v4.14.1","v5.0.0-rc.12","v5.0.0-rc.11","v5.0.0-rc.10","v4.14.0","v4.13.7","5.0.0-rc.9","5.0.0-rc.8","v5.0.0-rc.7","v5.0.0-rc.6","v5.0.0-rc.5","v5.0.0-rc.4","v5.0.0-rc.3","v5.0.0-rc.2","v5.0.0-rc.1","v5.0.0-rc.0","v4.13.6","v4.13.5","v4.13.4","v4.13.3","v4.13.2","v4.13.1","v4.13.0","v4.12.0","v4.11.0","v4.10.0","v4.9.9","v4.9.8","v4.9.7","v4.9.6","v4.9.5","v4.9.4","v4.9.3","v4.9.2","v4.9.1","v4.9.0","v4.8.7","v4.8.5","v4.8.4","v4.8.3","v4.8.2","v4.8.1","v4.8.0","v4.7.7","v4.7.6","v4.7.5","v4.7.4","v4.7.3","v4.7.2","v4.7.1","v4.7.0","v4.6.4","v4.6.3","v4.6.2","v4.6.1","v4.6.0","v4.5.6","v4.5.5","v4.5.4","v4.5.3","v4.5.2","v4.5.1","v4.4.9","v4.4.8","v4.4.7","v4.4.6","v4.4.5","v4.4.4","v4.4.3","v4.4.2","v4.4.1","v4.4.0","v4.3.12","v4.3.10","v4.3.9","v4.3.7","v4.3.6","v4.3.4","v4.3.3","v4.3.2","v4.3.1","v4.3.0","v4.2.7","v4.2.5","v4.2.3","v4.2.2","v4.2.1","v4.2.0","v4.1.0","v4.0.4","v4.0.3","v4.0.2","v4.0.1","v4.0.0","v4.0.0-rc.7","v4.0.0-rc.6","v4.0.0-rc.5","v4.0.0-rc.4","v4.0.0-rc.3","v4.0.0-rc.2","v4.0.0-rc.1","v4.0.0-rc.0","v3.12.4","v3.12.3","v3.12.2","v3.12.1","v3.12.0","v3.11.16","v3.11.15","v3.11.14","v3.11.13","v3.11.12","v3.11.10","v3.11.9","v3.11.8","v3.11.7","v3.11.6","v3.11.5","v3.11.4","v3.11.3","v3.11.2","v3.11.1","v3.11.0","v3.10.8","v3.10.7","v3.10.6","v3.10.5","v3.10.4","v3.10.2","v3.10.1","v3.10.0","v3.9.6","v3.9.5","v3.9.4","v3.9.3","v3.9.2","v3.9.0","v3.7.9","v3.7.8","v3.7.6","v3.7.5","v3.7.4","v3.7.3","v3.7.2","v3.7.1","v3.7.0","v3.6.1","v3.5.3","v3.5.2","v3.5.1","v3.5.0","v3.4.2","v3.4.1","v3.4.0","v3.3.1","v3.3.0","v3.2.2","v3.2.1","v3.2.0","v3.1.0","v3.0.4","v3.0.3","v3.0.2","v3.0.1","v3.0.0","v2.0.1","v2.0.0","v1.0.0","v0.6.1","v0.6.0","v0.5.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-82685.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}],"credits":[{"name":"Peter Ullrich","type":"REPORTER"},{"name":"James Harton","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"ANALYST"}]}