Critical
Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-23478
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 01:28 UTC · Revision 1
Source evidence
Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback
core-osv · Original sourcePublished 13 Jan 2026, 21:37 UTC
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.
osv:CVE-2026-23478
Complete source record
{
"id": "30e039ce41a2902ed9bd26929df0d0bd5e501873f3dae0010060959f0882933b",
"url": "https://osv.dev/vulnerability/CVE-2026-23478",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback",
"summary": "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.",
"evidence": "osv:CVE-2026-23478",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2026-23478",
"aliases": [
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"GHSA-7hg4-x4pr-3hrg"
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"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L"
}
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{
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],
"modified": "2026-10-28T02:30:48.561731525Z",
"provider": "osv",
"references": [
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"https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg",
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"source_id": "core-osv",
"document_id": 516985,
"published_at": "2026-01-13T21:37:35.541+00:00"
}