{"id":"CVE-2026-56668","aliases":["GHSA-vrh8-c9cm-wh8v"],"url":"https://o3.security/vulnerability/CVE-2026-56668","summary":"ZITADEL: Unauthorized Token Privilege Escalation in OAuth2 Token Exchange","details":"ZITADEL is an open source identity management platform. Prior to 4.15.3, ZITADEL's OAuth2 Token Exchange endpoint for urn:ietf:params:oauth:grant-type:token-exchange does not verify that the subject token belongs to the requesting client or that requested scopes remain within the original token's scopes, allowing a low-privilege token to be exchanged for elevated permissions at another application. This issue is fixed in version 4.15.3.","published":"2026-07-10T17:46:25.937Z","modified":"2026-08-12T03:51:15.464477779Z","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"epss":{"score":0.00231,"percentile":0.14029,"asOf":"2026-08-01"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/zitadel/zitadel","fixedVersion":"4.15.3"}],"fix":{"url":"https://github.com/zitadel/zitadel/commit/e2886a61670ca8fd41c9434f87036546e5620bcc","label":"zitadel/zitadel@e2886a6"},"references":[{"type":"WEB","url":"https://github.com/zitadel/zitadel/releases/tag/v4.15.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56668.json"},{"type":"ADVISORY","url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-vrh8-c9cm-wh8v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56668"},{"type":"FIX","url":"https://github.com/zitadel/zitadel/commit/e2886a61670ca8fd41c9434f87036546e5620bcc"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:15.464477779Z"}}