Vulnerability · Published Nov 3, 2026 · Assigned by EEF
CVE-2026-118505AshAuthentication brute_force_strategy does not limit sign-in and request actions defined on the resource
Medium 6.3
In plain English
A medium-severity security flaw in ash_authentication from team-alembic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Official description
Improper Restriction of Excessive Authentication Attempts vulnerability in team-alembic ash_authentication allows an unauthenticated attacker to guess passwords and one-time passwords without limit. The password, magic link and OTP strategies enforce brute_force_strategy by adding a preparation only to the actions they generate. When the resource defines one of those actions itself, the strategy uses it as written and nothing checked that it carried the preparation, so the setting compiled and applied no limit. The generators produce exactly this: mix ash_authentication.install writes sign_in_with_password, request_password_reset_token and request_magic_link, mix ash_authentication.upgrade then adds brute_force_strategy to those strategies, and mix ash_authentication.add_strategy.otp writes its OTP actions without the preparation. Separately, with registration_enabled? true the OTP sign-in is a create action, which preparations do not run on, so brute_force_strategy {:preparation, module} never applied to it. This issue affects ash_authentication: from 5.0.0-rc.4 before 5.0.0-rc.16.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| team-alembic | ash_authentication | 5.0.0-rc.4 – before 5.0.0-rc.16 |
| team-alembic | ash_authentication | 800caa0d4a5bee1f28ad427f4c12fab72003a577 – before 7117b5da5b73ee4cdb372e4adfbaff409b527125 |
Weakness: CWE-307 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
References
- `brute_force_strategy` in AshAuthentication does not protect sign-in and request actions defined on the resource, allowing unlimited password and one-time password guessing vendor-advisory, related
- EEF CNA record for CVE-2026-118505 related
- OSV record EEF-CVE-2026-118505 related
- Introducing commit 800caa0 in team-alembic/ash_authentication related
- Fix commit 7117b5d in team-alembic/ash_authentication patch