{"id":"CVE-2026-41213","summary":"@node-oauth/oauth2-server: PKCE code_verifier ABNF not enforced in token exchange allows brute-force redemption of intercepted authorization codes","details":"@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.","aliases":["GHSA-jhm7-29pj-4xvf"],"modified":"2026-08-12T03:51:12.273320977Z","published":"2026-04-23T18:33:42.365Z","database_specific":{"cwe_ids":["CWE-1289","CWE-307"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41213.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41213.json"},{"type":"ADVISORY","url":"https://github.com/node-oauth/node-oauth2-server/security/advisories/GHSA-jhm7-29pj-4xvf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41213"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/node-oauth/node-oauth2-server","events":[{"introduced":"0"},{"fixed":"cc70455a9496b184fd0caaadd79ba4b4002eb4c9"}],"database_specific":{"cpe":"cpe:2.3:a:node-oauth:node-oauth\\/oauth2-server:*:*:*:*:*:node.js:*:*","extracted_events":[{"introduced":"0"},{"fixed":"5.3.0"}],"source":["AFFECTED_FIELD","CPE_RANGE"]}}],"versions":["v5.2.2-rc.0","v5.2.1","v5.2.0","v5.1.0","v5.1.0-rc.0","v4.0.0","v3.1.1","v3.1.0","v3.0.2","v3.0.0","v3.0.0-b4","v3.0.0-b3.1","v3.0.0-b3","v2.4.1","v2.4.0","v2.3.0","v2.2.2","v2.2.1","v2.2.0","v1.5.2","v1.5.1","v1.5.0","v1.4.1","v1.4.0","v1.3.2","v1.3.1","v1.3.0","v1.2.5","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-41213.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}