Vulnerability Description
Authorization 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. 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. This 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.
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-82685.html
- https://github.com/team-alembic/ash_authentication/commit/1d4bb00617aecae85c33f2
- https://github.com/team-alembic/ash_authentication/commit/2a2396af131ab67e2f445b
- https://github.com/team-alembic/ash_authentication/commit/d7c15c21d39c009206e010
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-g636
- https://osv.dev/vulnerability/EEF-CVE-2026-82685
FAQ
What is CVE-2026-82685?
CVE-2026-82685 is a documented vulnerability. Authorization 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 ove...
How severe is CVE-2026-82685?
CVSS scoring is not yet available for CVE-2026-82685. Check NVD for updates.
Is there a patch for CVE-2026-82685?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.