EUVD-2026-38737Severity by source
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
Network-reachable endpoint, low complexity once IdP configured, but PR:H because attacker must be an enterprise org admin; scope changes across tenants so S:C with C:H/I:H and A:N.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
2DescriptionCVE.org
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.
AnalysisAI
Cross-domain SSO account takeover in Capgo before 12.128.2 allows an attacker with enterprise org admin access and a malicious IdP to forge SAML assertions and merge arbitrary victim accounts based solely on email match. The provision-user endpoint fails to validate that the asserting SSO provider is authorized for the victim's email domain, granting full takeover of accounts, organizations, and data. No public exploit identified at time of analysis; CVSS 4.0 base is 9.3 (Critical) reflecting high impact across both vulnerable and subsequent systems.
Technical ContextAI
Capgo is a live-update and OTA delivery platform for Capacitor-based mobile applications, offering enterprise SSO via SAML. The flaw is rooted in CWE-287 (Improper Authentication): the provision-user endpoint accepts a SAML assertion from any tenant's configured IdP and uses the asserted email address as the sole key for merging into an existing account, with no check that the asserting tenant/IdP owns or is authorized for that email's domain. This is a classic multi-tenant SSO trust-boundary failure where the application trusts identity claims across tenant boundaries rather than scoping each IdP to its verified domain(s).
RemediationAI
Vendor-released patch: upgrade Capgo to 12.128.2 or later, which adds domain-authorization validation to the provision-user endpoint so SAML email assertions are only honored for domains the asserting IdP is authorized for; see the upstream advisory at https://github.com/Cap-go/capgo/security/advisories/GHSA-jhjh-vp9p-54fg for fix details. If immediate upgrade is not possible, restrict creation of enterprise organizations and IdP configurations to vetted customers only, audit existing IdP-to-domain mappings and revoke any IdP that asserts domains it does not legitimately own, and temporarily disable automatic account-merge-on-email behavior in the provision-user flow (trade-off: legitimate SSO onboarding will require manual admin merge). Monitor provisioning logs for SAML assertions where the asserting org's verified domains do not match the asserted email domain and alert on cross-tenant merges.
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Account pre-registration hijack in Capgo before 12.128.2 lets a remote unauthenticated attacker claim an account under a
Authentication bypass in Capgo prior to version 12.128.2 lets attackers defeat email-based OTP verification by tampering
Rate-limit bypass in Capgo versions prior to 12.128.2 lets remote unauthenticated attackers flood the channel_self endpo
Cross-tenant data poisoning in Supabase Capgo before 12.128.2 allows remote unauthenticated attackers to corrupt billing
Server-side privilege escalation in Capgo before 12.128.2 lets authenticated users holding build permissions abuse a pat
Unauthenticated information disclosure in Capgo before 12.128.2 lets remote attackers query the /functions/v1/channel_se
Account takeover in Capgo before 12.128.2 stems from a password-change endpoint that omits current-password validation (
Information disclosure in Capgo (Capacitor live-update/OTA platform) before 12.128.2 lets unauthenticated callers abuse
Unauthenticated information disclosure in Capgo before 12.128.2 lets remote attackers read organization RBAC role bindin
Cross-tenant authorization bypass in Capgo before 12.128.2 lets authenticated users impersonate another tenant's limited
Privilege escalation in Capgo before 12.128.2 lets an authenticated org admin assign org-scoped RBAC roles at the narrow
Same weakness CWE-287 – Improper Authentication
View allSame technique Authentication Bypass
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External POC / Exploit Code
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