Open Redirect in Calcom Cal.diy
CVE-2026-63768
cal.diy through 6.2.0 contains an open redirect vulnerability in the conferencing OAuth callback endpoint that allows attackers to redirect users to arbitrary URLs by crafting malicious state parameters. Attackers can exploit the unsigned state parameter and onErrorReturnTo field to silently redirect visitors from the trusted domain to attacker-controlled URLs for phishing attacks.
Vulnerability class: Open Redirect
EPSS: 0.003 (27.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
Affected products
- Calcom Cal.diy — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking, technical-description, exploit)
- disclosure@vulncheck.com (issue-tracking, patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-63768?
- CVE-2026-63768 is a medium-severity vulnerability in Calcom Cal.diy, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-07-20.
- How severe is CVE-2026-63768?
- Medium severity. CVSS v3 base score is 4.3 out of 10.