{"id":"CVE-2026-59243","title":"The FAB auth manager's Azure AD OAuth login defaulted `verify_signature=False` when decoding the ID token, so an attacker able to present a forged or unsigned (`alg:none`) ID token to the OAuth callback could bypass authentication and lo…","summary":"The FAB auth manager's Azure AD OAuth login defaulted `verify_signature=False` when decoding the ID token, so an attacker able to present a forged or unsigned (`alg:none`) ID token to the OAuth callback could bypass authentication and lo…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-347"],"vendor":"apache","product":"apache-airflow-providers-fab","affected":["apache-airflow-providers-fab < 3.7.3"],"patched":["apache-airflow-providers-fab 3.7.3"],"published":"2026-07-29","updated":"2026-09-16","sourceUpdated":"2026-09-16T15:17:39.093","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-59243","references":[{"url":"https://github.com/apache/airflow/pull/69374","label":"security@apache.org"},{"url":"https://lists.apache.org/thread/x4784l7z00tl3gw4tv2dmvoon77rxgpl","label":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/07/28/10","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org","exploit-available"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-07-29T15:29:52.670228Z"},"epss":0.00445,"epssPercentile":0.37988,"exploits":{"github":2,"githubRepos":["https://github.com/MalHyuk/CVE-2026-59243","https://github.com/0xdak/CVE-2026-59243_exploit"],"checkedAt":"2026-09-21T15:29:49.600Z"},"exploitAvailable":true,"ingestedAt":"2026-09-08T17:06:31.890Z","slug":"CVE-2026-59243","body":"## Overview\n\nThe FAB auth manager's Azure AD OAuth login defaulted `verify_signature=False` when decoding the ID token, so an attacker able to present a forged or unsigned (`alg:none`) ID token to the OAuth callback could bypass authentication and log in as an arbitrary user, including one holding the Admin role (CWE-347). Deployments running the FAB auth manager with the Azure AD OAuth login path under its default configuration are affected; the Authentik path already defaulted to `True`. This issue affects `apache-airflow-providers-fab` before 3.7.3. Users are advised to upgrade to `apache-airflow-providers-fab` 3.7.3, which defaults `verify_signature=True`.\n\n## Affected\n\n- `apache-airflow-providers-fab < 3.7.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `apache-airflow-providers-fab 3.7.3`","depth":"abyssal","depthScore":66,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}