CVE-2026-56223 json
Capgo - Account Takeover via Cross-Domain SSO Email Assertion in provision-user
published 4mo ago modified 17d ago also EUVD-2026-38737
- cvss
- 8.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 34%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Capgo Capgo 12.128.2
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | 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 |
| CNA | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
| CNA | 4.0 | 9.3 | 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 |
Affected products
- Capgo Capgo
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
github.com
/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg
vendor-advisory, exploit
-
vulncheck.com
/advisories/capgo-account-takeover-via-cross-domain-sso-email-assertion-in-provision-user
third-party-advisory
Sources
- CVE List CVE-2026-56223
- NVD CVE-2026-56223
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