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Vulnerabilities

Vulnerability · CVE-2026-23478

Cal.com is open-source scheduling software.

Published Jan 13, 2026 · catalog updated Jan 14, 2026 · Cal.com is open-source scheduling

Last checked Nov 6, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-23478. EPSS is 0.47%. Act only if a listed version of Cal.com is open-source scheduling is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Cal.com is open-source scheduling).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Critical10.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.47%
Remediation
Version ranges on file
Affected products
vendor calcom cal.com 3.1.6, < 6.0.7

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor calcom cal.com 3.1.6, < 6.0.73.1.6, < 6.0.7

How to fix CVE-2026-23478

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-23478. EPSS is 0.47%. Act only if a listed version of Cal.com is open-source scheduling is installed.

Which versions are affected?

Compare what you have installed with calcom cal.com 3.1.6, < 6.0.7 3.1.6, < 6.0.7. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.47%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 13, 2026 · EUVD

    Detected

    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.

  2. Jan 14, 2026 · EUVD

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-2026-23478

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-23478

    30-day exploitation probability 0.47%

    first.org
  • EUVDVulnerability recordEUVD-2026-2413

    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 vulnerab

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 6, 2026
  • CVE.orgOct 30, 2026
  • EUVDOct 30, 2026