What’s Vulnerable › Vulnerabilities
CVE-2026-23478: Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback
- Severity: critical (CVSS 9.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-01-13 · updated 2026-06-17
- Weakness: CWE-602
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.
Affected products
- calcom cal.com: from 3.1.6 before 6.0.7 — fixed in 6.0.7
How to fix
Upgrade to a fixed version: calcom cal.com 6.0.7. Check the vendor advisory for mitigations.
References
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