CVE-2026-56223

critical · 9.3

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.

9.3

CVSS

0.3%

EPSS (exploit prob.)

23rd

EPSS percentile

2026-06-24

Published

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weaknesses

CWE-287

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

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-56223