{"id":"CVE-2026-23478","aliases":["EUVD-2026-2413","GHSA-7hg4-x4pr-3hrg"],"status":"published","title":"Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback","description":"Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.","severity":{"version":"4.0","score":10,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00466,"percentile":0.40646,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-602","CWE-639"],"published":"2026-01-13T21:37:35Z","modified":"2026-10-28T02:30:48Z","products":[{"vendor":"cal","product":"cal.com"},{"vendor":"calcom","product":"cal.com"}],"references":[{"url":"https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg","tags":["x_refsource_CONFIRM","Third Party Advisory","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23478.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23478","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-23478","title":"Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback","description":"Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.","status":"published","published":"2026-01-13T21:37:35.541Z","modified":"2026-01-14T16:56:25.582Z","cvss":[{"version":"4.0","score":10,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L","level":"critical","assessor":"cna"}],"cwes":["CWE-602","CWE-639"],"updated_at":"2026-11-02T13:42:04.39372Z"}],"euvd":[{"id":"EUVD-2026-2413","description":"Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.","status":"published","published":"2026-01-13T21:37:35Z","modified":"2026-01-14T16:56:25Z","cvss":[{"version":"4.0","score":10,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L","level":"critical"}],"updated_at":"2026-11-02T19:48:51.744142Z"}],"nvd":[{"id":"CVE-2026-23478","description":"Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.","status":"published","published":"2026-01-13T22:16:08.093Z","modified":"2026-06-17T10:21:39.57Z","cvss":[{"version":"4.0","score":10,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","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-602","CWE-639"],"updated_at":"2026-11-02T14:12:04.066712Z"}],"osv":[{"id":"CVE-2026-23478","title":"Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback","description":"Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.","status":"published","published":"2026-01-13T21:37:35.541Z","modified":"2026-10-28T02:30:48.561731525Z","cvss":[{"version":"4.0","score":10,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L","level":"critical"}],"cwes":["CWE-602","CWE-639"],"updated_at":"2026-11-02T15:44:59.079784Z"}]}}