CVE-2026-81637: falha de baixa gravidade em team-alembic ash_authentication
Replayable OAuth2 CSRF state retained after a failed callback in AshAuthentication
Publicada em
Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.
8Vexday Risk Score
Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.
ssvc Trackcvss 2.3epss 0.6%
Insufficient Session Expiration vulnerability in team-alembic AshAuthentication allows an attacker who obtains a victim's OAuth2 state value to replay the callback and sign that victim into an attacker-controlled account.
AshAuthentication.Strategy.OAuth2.Plug.callback/2 clears the stored session_params through a rebinding step inside its with chain, conn <- delete_session(conn, session_key). Elixir evaluates the else block in the scope enclosing the with, so every failure path (the provider returning ?error=access_denied, an invalid code, a token-exchange error, or a registration or sign-in failure) reaches store_authentication_result/2 holding the original connection and the session entry is never removed. The value the module's own comment describes as protection against a CSRF-related attack is therefore consumed only when authentication succeeds, and survives a cancelled or failed attempt until the next request phase or session expiry.
This issue affects ash_authentication: from 0.6.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Produtos afetados
team-alembic · ash_authenticationCVEs relacionadas — team-alembic ash_authentication
No mesmo produto, das mais perigosas para as menos.
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%
Referências
https://cna.erlef.org/cves/CVE-2026-81637.htmlhttps://github.com/team-alembic/ash_authentication/commit/bd4352303bc9d72d007f6818775267585a4bcc2fhttps://github.com/team-alembic/ash_authentication/commit/c5f589058e04239263f50a1430eb17ea6d5dd1a2https://github.com/team-alembic/ash_authentication/commit/d7f939cd02bd618bcaa304631846fa75ffc419d7https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-3vcj-gxx8-3p44https://osv.dev/vulnerability/EEF-CVE-2026-81637