CVE-2026-56223

Capgo before 12.128.2 contains a cross-domain SSO account takeover vulnerability in the provision-user endpoint that allows attackers to merge arbitrary victim accounts based on email match without validating SSO provider domain authorization. An attacker with enterprise org admin access and a malicious IdP can forge SAML assertions containing victim email addresses to trigger account merge and gain full access to victim accounts, organizations, and data.

CVSS 4.0

9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

CVSS 3.1

8.7CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-287

Published

2026-06-24

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

References

• https://github.com/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg
• https://www.vulncheck.com/advisories/capgo-account-takeover-via-cross-domain-sso-email-assertion-in-provision-user
• https://github.com/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg

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