Authorization Bypass Through User-Controlled Key vulnerability in team-alembic ash_authentication allows a user with an account to install a TOTP secret they control on another user's account, and then sign in as that user or hold their second factor.

AshAuthentication.Strategy.Totp.ConfirmSetupChange verified a setup token but did not check that it was issued to the record being confirmed, so an attacker's own pending secret could be confirmed onto another user's record. The TOTP setup changes, ConfirmSetupChange, GeneratePendingSetupChange and GenerateSecretChange, also marked their changesets as AshAuthentication interactions, which the standard AshAuthenticationInteraction policy bypass lets through. A policy limiting setup and confirm_setup to the actor's own record therefore never ran when an application exposed those actions by record key, and a direct setup call on another user's record returned that user's pending secret and setup token.

This issue affects ash_authentication: from 5.0.0-rc.0 before 5.0.0-rc.16.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

Do not expose setup or confirm_setup on a record the caller chooses. Call them through AshAuthentication.Strategy.Totp.Actions with the signed-in user, as the built-in routes do.

History

Tue, 03 Nov 2026 16:00:00 +0000

Type Values Removed Values Added
Description Authorization Bypass Through User-Controlled Key vulnerability in team-alembic ash_authentication allows a user with an account to install a TOTP secret they control on another user's account, and then sign in as that user or hold their second factor. AshAuthentication.Strategy.Totp.ConfirmSetupChange verified a setup token but did not check that it was issued to the record being confirmed, so an attacker's own pending secret could be confirmed onto another user's record. The TOTP setup changes, ConfirmSetupChange, GeneratePendingSetupChange and GenerateSecretChange, also marked their changesets as AshAuthentication interactions, which the standard AshAuthenticationInteraction policy bypass lets through. A policy limiting setup and confirm_setup to the actor's own record therefore never ran when an application exposed those actions by record key, and a direct setup call on another user's record returned that user's pending secret and setup token. This issue affects ash_authentication: from 5.0.0-rc.0 before 5.0.0-rc.16.
Title AshAuthentication TOTP setup lets a user install their own authenticator secret on another user's account
First Time appeared Team-alembic
Team-alembic ash Authentication
Weaknesses CWE-639
CPEs cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*
Vendors & Products Team-alembic
Team-alembic ash Authentication
References
Metrics cvssV4_0

{'score': 7.6, 'vector': '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-11-03T17:49:28.211Z

Reserved: 2026-11-03T03:30:01.648Z

Link: CVE-2026-119215

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-03T16:17:21.683

Modified: 2026-11-03T16:17:21.810

Link: CVE-2026-119215

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-03T17:30:08Z

Weaknesses