{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.1.0"
              },
              {
                "fixed": "0.3.1"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "a4d8c361f710e5a050a1cf4834c9fa6c8f3dbd01"
            },
            {
              "fixed": "15bde4311e31c925a428f34c02b283307619e2a2"
            },
            {
              "fixed": "a72972d7ed3eb74c05dfa0653a258ef14454459a"
            }
          ],
          "repo": "https://github.com/ash-project/ash_authentication_oauth2_server",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-wwxg-h779-3wf4"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-424"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82754.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "855b578037c5ded18e8a6e60f42e56bde4905fae"
          },
          {
            "fixed": "a72972d7ed3eb74c05dfa0653a258ef14454459a"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "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.\n\noauth2_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.\n\nThis issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1.",
  "id": "CVE-2026-82754",
  "modified": "2026-09-10T03:30:55.092073667Z",
  "published": "2026-09-07T22:23:56.762Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-82754.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-82754"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82754.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-wwxg-h779-3wf4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82754"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ash-project/ash_authentication_oauth2_server/commit/a72972d7ed3eb74c05dfa0653a258ef14454459a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ash-project/ash_authentication_oauth2_server"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ash_authentication_oauth2_server aliases every protocol endpoint under /.well-known, bypassing path-scoped controls"
}