CVE-2026-118505 Details
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.
A vulnerability in the Ash Authentication library by Team Alembic, specifically in versions 5.0.0-rc.4 prior to 5.0.0-rc.16, allows unauthenticated attackers to guess passwords and one-time passwords (OTPs) without any limitations. This issue arises because the library's brute force protection strategy is not properly applied to all actions, particularly those defined manually on the resource. As a result, attackers can exploit this flaw to repeatedly attempt to guess passwords and OTPs, potentially bypassing authentication mechanisms.
Update to Ash Authentication version 5.0.0-rc.16 or later, where this vulnerability has been fixed. If using an earlier version, add the necessary brute force preparation to each protected action or remove the action so that the strategy can generate it automatically. For OTP authentication with registration enabled, switch to the 'rate_limit' strategy.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 3, 2026CISA-ADP
Assessed Nov 3, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://cna.erlef.org/cves/CVE-2026-118505.html | EEF | AdvisoryBundle |
| https://github.com/team-alembic/ash_authentication/commit/7117b5da5b73ee4cdb372e4adfbaff409b527125 | EEF | Source CodeVendor |
| https://github.com/team-alembic/ash_authentication/commit/800caa0d4a5bee1f28ad427f4c12fab72003a577 | EEF | Source CodeVendor |
| https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-55gf-3263-4r39 | EEF | AdvisoryRemedyVendor |
| https://osv.dev/vulnerability/EEF-CVE-2026-118505 | EEF | AdvisoryBundle |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-307 | Improper Restriction of Excessive Authentication Attempts | EEF |
Affected Products
| Product | Versions |
|---|---|
| team-alembic ash_authentication | >= 5.0.0-rc.4, < 5.0.0-rc.16 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 3, 2026 | CVE Modified | CISA-ADP |
| Nov 3, 2026 | New CVE Received | EEF |
Volerion