Vulnerability from bitnami_vulndb
Published
2026-04-16 23:36
Modified
2026-04-17 00:10
Summary
OAuth2: PKCE can be fully circumvented
Details

authentik is an open-source identity provider. When initialising a oauth2 flow with a code_challenge and code_method (thus requesting PKCE), the single sign-on provider (authentik) must check if there is a matching and existing code_verifier during the token step. Prior to versions 2023.10.4 and 2023.8.5, authentik checks if the contents of code_verifier is matching only when it is provided. When it is left out completely, authentik simply accepts the token request with out it; even when the flow was started with a code_challenge. authentik 2023.8.5 and 2023.10.4 fix this issue.

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "authentik",
        "purl": "pkg:bitnami/authentik"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2023.8.5"
            },
            {
              "introduced": "2023.10.0"
            },
            {
              "fixed": "2023.10.4"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-48228"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*"
    ],
    "severity": "Critical"
  },
  "details": "authentik is an open-source identity provider. When initialising a oauth2 flow with a `code_challenge` and `code_method` (thus requesting PKCE), the single sign-on provider (authentik) must check if there is a matching and existing `code_verifier` during the token step. Prior to versions 2023.10.4 and 2023.8.5, authentik checks if the contents of `code_verifier` is matching only when it is provided. When it is left out completely, authentik simply accepts the token request with out it; even when the flow was started with a `code_challenge`. authentik 2023.8.5 and 2023.10.4 fix this issue.",
  "id": "BIT-authentik-2023-48228",
  "modified": "2026-04-17T00:10:47.507Z",
  "published": "2026-04-16T23:36:07.745Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/blob/dd4e9030b4e667d3720be2feda24c08972602274/authentik/providers/oauth2/views/token.py#L225"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/commit/3af77ab3821fe9c7df8055ba5eade3d1ecea03a6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/commit/6b9afed21f7c39f171a4a445654cfe415bba37d5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/commit/b88e39411c12e3f9e04125a7887f12354f760a14"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/pull/7666"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/pull/7668"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/pull/7669"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2023.10.4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2023.8.5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/security/advisories/GHSA-fm34-v8xq-f2c3"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-48228"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "OAuth2: PKCE can be fully circumvented"
}


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