CVE-2026-88864: Cap-go capgo.app · Improper Access Control
Affects Cap-go capgo.appSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical.
Data as of 10/25/2026, 16:58:58 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wild: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Cap-gocapgo.app | Affected
| Fixed in– |
GitHubcap-go/capgo.apppkg:github/cap-go/capgo.appOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, restrict API key distribution and monitor for suspicious activity related to SSO provider entries. Avoid exposing the public.sso_providers table through PostgREST or implement additional access controls to prevent unauthorized writes.
Description
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.
Impact
Attackers can bypass intended backend SSO provisioning controls and create forged SSO provider entries that are trusted by the system. This allows enforcement of SSO policies on arbitrary domains without verification, disrupting normal login processes and potentially causing denial of service or unauthorized access scenarios related to SSO enforcement. The vulnerability has a critical CVSS 4.0 score of 9.3, indicating high impact with no required privileges or user interaction for exploitation.