CVE-2026-86533

Improper Output Neutralization for Logs vulnerability in team-alembic AshAuthentication allows an unauthenticated attacker to forge application log entries by submitting a password reset identity containing newlines or control characters. AshAuthentication.Strategy.Password.RequestPasswordReset.run/3 interpolates the identity argument into its Logger.warning/1 heredocs without escaping, truncating or type-restricting it. This issue affects ash_authentication: from 4.2.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

An inefficient algorithmic complexity vulnerability in AshAuthentication allows an unauthenticated attacker to exhaust CPU and memory via an oversized base62 segment in an API key. The decoding functions have quadratic/cubic complexity and do not limit input length.

An authorization bypass vulnerability in AshAuthentication allows an authenticated attacker to overwrite and confirm another user's email address, leading to account takeover. A confirmation token issued for one user is accepted on another user's record.

An improper authentication vulnerability in AshAuthentication allows an attacker with a sign-in token for one authenticated resource to be signed in as a user of a different resource. The issue arises from incorrect parsing of the sub claim in the JWT token.

Vulnerability in AshAuthentication library (versions from 0.2.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14) concerning improper verification of cryptographic signature. The token revocation mechanism does not verify signature, allowing an attacker to neutralize revocations or write arbitrary rows into the token resource.

Authentication Bypass by Primary Weakness vulnerability in team-alembic AshAuthentication allows an unconfirmed user to obtain a session, defeating a mandatory email confirmation requirement. check_user/2 decides whether the require_confirmed_with attribute is set using a bare is_nil(Map.get(user, value)); when the attribute is not loaded it returns %Ash.NotLoaded{} and when a field policy denies it returns %Ash.ForbiddenField{}, neither of which is nil, so the rejection branch is skipped. Additionally, the check is not enforced when the action is invoked directly by an API layer such as AshGraphql or AshJsonApi.

Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in team-alembic AshAuthentication allows an attacker holding a leaked magic link to replay its single-use token and authenticate as the target subject. Nothing serialises the token's validity check against its consumption, so concurrent redemptions of one token all succeed and each yields a full user token. Revocation happens only after JWT verification, and the revocation is written as an upsert, so a concurrent duplicate revocation silently succeeds.

A reflected XSS vulnerability in the AshAuthentication library allows an attacker to inject malicious script into HTML pages generated during action confirmation or magic link sign-in. The issue occurs when a strategy has require_interaction enabled and request parameters are embedded into forms without proper escaping.

A vulnerability in the AshAuthentication library allows one-time JWTs (e.g., WebAuthn sign-in tokens) to be replayed as full bearer API credentials. This is due to missing purpose claim validation in the stateless bearer-token verification path.