Auth bypass in Capgo
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (32.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Capgo — versions 0, 12.128.2
Weakness classification (CWE)
References
- github.com/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg (vendor-advisory)
- www.vulncheck.com/advisories/capgo-account-takeover-via-cross-domain-sso-email-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56223?
- CVE-2026-56223 is a high-severity vulnerability in Capgo, classified under Improper Authentication. CVSS score: 8.7/10. Published 2026-06-24.
- How severe is CVE-2026-56223?
- High severity. CVSS v3 base score is 8.7 out of 10.