{"id":"CVE-2026-23478","state":"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.","publishedAt":"2026-01-13T21:37:35.541Z","updatedAt":"2026-01-14T16:56:25.582Z","severity":{"score":10,"label":"Critical","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["calcom cal.com"],"affected":[{"vendor":"calcom","product":"cal.com","versions":[{"version":">= 3.1.6, < 6.0.7","status":"affected"}]}],"references":["https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg"],"weaknesses":["CWE-602","CWE-639"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23478.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23478","state":"PUBLISHED","datePublished":"2026-01-13T21:37:35.541Z","dateUpdated":"2026-01-14T16:56:25.582Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-13T15:47:41.627Z"},"containers":{"cna":{"title":"Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"calcom","product":"cal.com","versions":[{"version":">= 3.1.6, < 6.0.7","status":"affected"}]}],"references":[{"url":"https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg","name":"https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"LOW","baseScore":10,"baseSeverity":"CRITICAL","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-602","lang":"en","description":"CWE-602: Client-Side Enforcement of Server-Side Security","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639: Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-01-13T21:37:35.541Z"},"source":{"advisory":"GHSA-7hg4-x4pr-3hrg","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-14T16:56:18.762218Z","id":"CVE-2026-23478","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-14T16:56:25.582Z"}}]}}}