CVE-2026-23478: critical vulnerability in calcom cal.com
Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 10epss 0.5%
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.
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
Affected products
calcom · cal.comRelated CVEs — calcom cal.com
In the same product, most dangerous first.
CVE-2025-66489CRITICALCal.com Authentication Bypass via bad TOTP + password checksEPSS 1.0%CVE-2026-112043MEDIUMcalcom cal.com/cal.diy Webhook util.ts createWebhookProcedure authorizationEPSS 0.4%CVE-2023-37919MEDIUMCal.com not expiring old sessions after enabling 2FAEPSS 0.3%CVE-2026-109143MEDIUMcalcom cal.com/cal.diy Credentials delete credentials.delete privileges managementEPSS 0.2%