Phishing redirects via unsigned OAuth callback state
Published Jul 20, 2026 · Updated Jul 20, 2026
Open redirect in Cal.diy 6.2.0 and earlier allows remote attackers to send visitors to arbitrary URLs through a crafted OAuth callback. The unauthenticated conferencing callback parses unsigned state JSON and returns its unvalidated onErrorReturnTo value as a 301 Location when error is set. A visitor must follow the crafted trusted-domain link; the redirect can deliver that visitor to an attacker-controlled phishing site.
Summary
What happened
Open redirect in Cal.diy 6.2.0 and earlier allows remote attackers to send visitors to arbitrary URLs through a crafted OAuth callback. The unauthenticated conferencing callback parses unsigned state JSON and returns its unvalidated onErrorReturnTo value as a 301 Location when error is set. A visitor must follow the crafted trusted-domain link; the redirect can deliver that visitor to an attacker-controlled phishing site.
The record
- CVE
- CVE-2026-63768
- Published
- Jul 20, 2026
- Updated
- Jul 20, 2026
- Vendor
- Cal.com, Inc.
- Product
- Cal.diy
- Classifications
- CWE-601, T1566.002, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 20, 2026CVE publishedPublication date reported by the CVE source.
- Jul 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=6.2.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Unsigned conferencing OAuth callback redirect PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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