ash_authentication_oauth2_server aliases every protocol endpoint under /.well-known, bypassing path-scoped controls
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ash-project | ash_authentication_oauth2_server | 0.1.0 to before 0.3.1 | 0.3.1 | Patch available | CNA |
- ash_authentication_oauth2_server Vendorash-project Affected 0.1.0 to before 0.3.1 Fixed in 0.3.1 Patch available CNA
CPE names CNA · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:* | — | — | — |
- cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:* Versions — — ·—
Remediation
- Fix · CNA ash_authentication_oauth2_server (ash-project) Fixed in 0.3.1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
ash-project ash_authentication_oauth2_server 0.3.1
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-57071 Resource allocation without limits in ash-project ash_authentication_oauth2_serverPriority LOW 37
- TI-2026-57076 Improper authentication in ash-project ash_authentication_oauth2_serverPriority LOW 29
- TI-2026-57075 ash_authentication_oauth2_server CIMD fetcher classifies IPv4-in-IPv6 and site-local addresses as public, allowing SSRFPriority LOW 29
Timeline
- 2026-10-02 Threatist record created from CVE-2026-82754
References
More ash-project vulnerabilities
- TI-2026-56298 Query-complexity limit bypass via first/last pagination arguments in AshGraphql enables denial of service CVSS 4.0HIGH 8.7
- TI-2026-52572 Unbounded atom creation from client-supplied RPC field names in AshTypescript field formatter CVSS 4.0HIGH 8.7
- TI-2026-57010 Path traversal in AshAdmin file uploads via unsanitized client filename CVSS 4.0HIGH 8.3
- TI-2026-26840 Ash Framework: Ash.Type.Module.cast_input/2 atom exhaustion via unchecked Module.concat allows BEAM VM crash CVSS 4.0HIGH 8.2
- TI-2026-54252 EEx template evaluation of prompt content in AshAi enables remote code execution CVSS 4.0HIGH 8.9
- TI-2026-54208 Stored XSS in AshAdmin relationship typeahead via unescaped label_field content CVSS 4.0HIGH 8.4
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences