EEF-CVE-2026-82754
- Source
- https://cna.erlef.org/osv/EEF-CVE-2026-82754.html
- Import Source
- https://cna.erlef.org/osv/EEF-CVE-2026-82754.json
- JSON Data
- https://api.osv.dev/v1/vulns/EEF-CVE-2026-82754
- Aliases
-
- GHSA-wwxg-h779-3wf4
- CVE-2026-82754
- Published
- 2026-09-07T22:23:56Z
- Modified
- 2026-09-07T22:30:03Z
- Severity
-
- 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- ash_authentication_oauth2_server aliases every protocol endpoint under /.well-known, bypassing path-scoped controls
- Details
-
Summary
Improper Protection of Alternate Path vulnerability in ash-project ash_authentication_oauth2_server exposes the state-changing OAuth endpoints under an unintended URL prefix, bypassing controls scoped to the canonical prefix.
oauth2_server_protocol_routes/1 in AshAuthentication.Phoenix.Oauth2Server.Router forwards the same ProtocolRouter at both the /oauth prefix and the /.well-known prefix. Phoenix forward strips the matched prefix before dispatch, so the full route table answers under both mounts, and POST /register, POST /token, and POST /revoke are reachable as /.well-known/register, /.well-known/token, and /.well-known/revoke. Edge controls such as WAF rules, rate limits, or authentication exemptions written against the /oauth paths, or that allow-list /.well-known as unauthenticated, do not apply to the alias.
This issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1.
Configuration
The routing alias is unconditional. Exploitable impact depends on the deployment applying path-scoped edge controls (WAF, rate limiting, auth-redirect exemptions) to the /oauth prefix, or allow-listing /.well-known as unauthenticated, that the alias then bypasses.
- Database specific
{ "capec_ids": [ "CAPEC-554" ], "cpe_ids": [ "cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*" ], "cwe_ids": [ "CWE-424" ] }- References
-
- https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-wwxg-h779-3wf4
- https://cna.erlef.org/cves/CVE-2026-82754.html
- https://github.com/ash-project/ash_authentication_oauth2_server/commit/a72972d7ed3eb74c05dfa0653a258ef14454459a
- https://hex.pm/packages/ash_authentication_oauth2_server
- Credits
-
-
- Peter Ullrich - FINDER
-
- Peter Ullrich - REPORTER
-
- Zach Daniel / Ash Project - REMEDIATION_DEVELOPER
-
- Jonatan Männchen / EEF - COORDINATOR
-
Affected packages
Hex / ash_authentication_oauth2_server
Package
- Name
- ash_authentication_oauth2_server
- Purl
- pkg:hex/ash_authentication_oauth2_server