{"cve":"CVE-2026-67335","nvd":{"published":"2026-08-01T13:17:04.403","modified":"2026-09-08T20:34:34.997","status":"Deferred","description":"better-auth versions before 1.6.2 fail to validate the OAuth state parameter against the stored nonce when using cookie-backed state storage without PKCE. Attackers can forge the state parameter and supply an attacker-controlled authorization code to create authenticated sessions bound to the attacker's external identity or persistently link attacker accounts to victim profiles.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":6.0},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","score":5.3},"cwes":["CWE-287"],"references":["https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr","https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:47:10.050265369+00:00"},"epss":{"cve":"CVE-2026-67335","score":0.00283,"percentile":0.20878,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-wxw3-q3m9-c3jr","url":"https://osv.dev/vulnerability/GHSA-wxw3-q3m9-c3jr","summary":"Better Auth: OAuth callback accepts mismatched `state` when cookie-backed state storage is used without PKCE","modified":"2026-08-02T03:56:45.903621172Z","packages":[{"ecosystem":"npm","name":"better-auth","purl":"pkg:npm/better-auth","ranges":["<1.6.2"],"fixed":["1.6.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}