CVE-2026-63768 calcom CVE debrief

Who should care

Defenders responsible for systems using cal.diy should assess exposure and prioritize verification and remediation efforts. Defenders should verify the cal.diy version in their inventory and assess exposure, especially in systems using the affected cal.diy version. The vulnerability has a medium severity and defenders should prioritize verifying the vulnerability in their inventory and assessing exposure, especially in systems using the affected cal.diy.

Why it matters

CVE-2026-63768 is a medium-severity open redirect vulnerability in cal.diy that allows attackers to redirect users to arbitrary URLs for phishing attacks. Defenders should prioritize verifying the vulnerability in their inventory and assessing exposure, especially in systems using the affected cal.diy version.

• Phishing attacks may be conducted by redirecting users to attacker-controlled URLs
• Defenders need to verify the vulnerability in their inventory and assess exposure
• Remediation priority is medium due to the potential for phishing attacks
• Verification of affected versions and scope is required

Technical summary

The CVE-2026-63768 vulnerability exists in the conferencing OAuth callback endpoint of cal.diy through version 6.2.0. The vulnerability allows attackers to redirect users to arbitrary URLs by crafting malicious state parameters. This issue can be exploited for phishing attacks by redirecting visitors from a trusted domain to attacker-controlled URLs. The vulnerability has a medium severity and defenders should prioritize verifying the vulnerability in their inventory and assessing exposure, especially in systems using the affected cal.diy version.

Defensive priority

Defenders should prioritize verifying the vulnerability in their inventory and assessing exposure, especially in systems using the affected cal.diy version.

Recommended defensive actions

• Verify the cal.diy version in your inventory and assess exposure
• Review and update the cal.diy version to a fixed version if available
• Monitor for potential phishing attacks using the vulnerable endpoint
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details about the vulnerability. However, the exact scope of affected systems and versions requires verification from the official sources. Defenders should verify the cal.diy version in their inventory and assess exposure, especially in systems using the affected cal.diy version. The vulnerability exists in the conferencing OAuth callback endpoint of cal.diy through version 6.2.0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.