Capgo SSO Provider Authentication Bypass via PostgREST Direct Write

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Capgo (capgo.app) fails to restrict direct write access to the public.sso_providers table exposed through Supabase PostgREST. A holder of an ordinary Capgo full API key can insert a row with status='active' and enforce_sso=true, bypassing the intended backend SSO provisioning route (supabase/functions/_backend/private/sso/providers.ts) and its controls: the Enterprise plan requirement, SSO provider creation via the Supabase Management API, DNS TXT domain-ownership verification, the pending_verification → verified → active status transition, and issuance of a trusted provider ID by Supabase Auth. The forged row is trusted by SSO discovery and enforcement logic, including the unauthenticated login preflight endpoint /private/sso/check-domain, which then reports {"has_sso": true, "enforce_sso": true} for domains that were never verified, allowing attacker-controlled SSO enforcement to be asserted for arbitrary domains and disrupting normal login. All versions are affected; at the time of the advisory no patch was available.

Source published

10 Sep 2026 13:05:20 UTC

Source modified

30 Sep 2026 17:20:34 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

CVSS 3.1 · 9.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:L