Skip to main content
← All vulnerabilities
CVE-2026-82758

ash_authentication_oauth2_server treats an empty resolved secret as valid, opening the gated Dynamic Client Registration endpoint

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.3.1
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

Improper Authentication vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to register OAuth clients even when Dynamic Client Registration is gated by an initial access token. resolve_secret/3 in AshAuthentication.Oauth2Server (reached through __resolve_secret__!) treated any return other than {:ok, _} or :error from a configured {module, function, args} or 2-arity-function secret provider as a valid secret, wrapping nil, false, or "" as {:ok, value}. When the initial_access_token resolves to such an empty value, POST /oauth/register compares the presented bearer token against it and the comparison passes with no token supplied, so registration is open although it was configured closed. The same fail-open affected other resolved secrets such as signing_secret. This issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • ash_authentication_oauth2_server

    From 0.1.0 · fixed in 0.3.1

  • ash-project/ash_authentication_oauth2_server

    Version range not reported

References 4

GitHub · ash-project/ash_authentication_oauth2_server

cna.erlef.org

osv.dev