{"id":"CVE-2023-48228","aliases":["BIT-authentik-2023-48228","EUVD-2023-52300","GHSA-fm34-v8xq-f2c3"],"status":"published","title":"OAuth2: PKCE can be fully circumvented","description":"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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01247,"percentile":0.69715,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287"],"published":"2023-11-21T20:48:32Z","modified":"2026-10-28T02:30:55Z","fixes":[{"ecosystem":"Bitnami","package":"authentik","fixed_in":["2023.8.5","2023.10.4"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"authentik","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2023.8.5"},{"introduced":"2023.10.0"},{"fixed":"2023.10.4"}]}]}],"products":[{"vendor":"goauthentik","product":"authentik"}],"references":[{"url":"https://github.com/goauthentik/authentik/security/advisories/GHSA-fm34-v8xq-f2c3","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Vendor Advisory","advisory"]},{"url":"https://github.com/goauthentik/authentik/pull/7666","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/pull/7668","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/pull/7669","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/commit/3af77ab3821fe9c7df8055ba5eade3d1ecea03a6","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/commit/6b9afed21f7c39f171a4a445654cfe415bba37d5","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/commit/b88e39411c12e3f9e04125a7887f12354f760a14","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://github.com/goauthentik/authentik/blob/dd4e9030b4e667d3720be2feda24c08972602274/authentik/providers/oauth2/views/token.py#L225","tags":["x_refsource_MISC","x_transferred","Product","web"]},{"url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2023.10.4","tags":["x_refsource_MISC","x_transferred","Release Notes","article","web"]},{"url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2023.8.5","tags":["x_refsource_MISC","x_transferred","Release Notes","article","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-48228","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/48xxx/CVE-2023-48228.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2023-48228","title":"OAuth2: PKCE can be fully circumvented","description":"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.","status":"published","published":"2023-11-21T20:48:32.552Z","modified":"2024-08-02T21:23:39.088Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:35:25.866071Z"}],"euvd":[{"id":"EUVD-2023-52300","description":"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.","status":"published","published":"2023-11-21T20:48:32Z","modified":"2024-08-02T21:23:39Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-03T03:49:57.383318Z"}],"nvd":[{"id":"CVE-2023-48228","description":"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.","status":"published","published":"2023-11-21T21:15:08.477Z","modified":"2026-06-17T06:33:47.157Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:08:47.966245Z"}],"osv":[{"id":"CVE-2023-48228","title":"OAuth2: PKCE can be fully circumvented","description":"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.","status":"published","published":"2023-11-21T20:48:32.552Z","modified":"2026-10-28T02:30:55.574976635Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T15:44:34.72355Z"},{"id":"BIT-authentik-2023-48228","title":"OAuth2: PKCE can be fully circumvented","description":"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.","status":"published","published":"2026-04-16T23:36:07.745Z","modified":"2026-09-08T08:45:35.507313875Z","updated_at":"2026-11-02T15:28:28.70813Z"}]}}