CVE-2026-82685highCWE-639

CVE-2026-82685: high-severity vulnerability in team-alembic ash_authentication

Confirmation token accepted on any record in AshAuthentication

Published

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.6epss 0.7%
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.
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
Affected products
team-alembic · ash_authentication
Related CVEs — team-alembic ash_authentication

In the same product, most dangerous first.

CVE-2026-86533CRITICALRevoked session accepted because the session jti is never checked in AshAuthentication and AshAuthentication PhoenixEPSS 0.9%CVE-2026-76949CRITICALRemember-me sign-in guard reads a session key that is never written in ash_authentication, allowing session replacementEPSS 0.8%CVE-2026-85500CRITICAL`require_confirmed_with` is not enforced on the action and fails open on an unreadable attribute in AshAuthenticationEPSS 0.8%CVE-2026-66882LOWReflected XSS in AshAuthentication confirmation and magic link interaction formsEPSS 0.8%CVE-2026-88952CRITICALOAuth2 sign-in attached to an existing account without an email comparison in AshAuthenticationEPSS 0.7%CVE-2026-86688HIGHSession id is not renewed on authentication in ash_authentication, allowing session fixationEPSS 0.7%