CVE-2026-88864

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-10. a secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.1
EG Score
9.1(high)
EG Risk
57(Track*)
EG Risk 57/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 10, 2026

Last Modified

September 10, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Direct PostgREST writes to sso_providers bypass Enterprise/DNS verification and poison SSO login discovery · Advisory · Cap-go/capgo.app · GitHub

https://github.com/Cap-go/capgo.app/security/advisories/GHSA-xg7v-83qv-qfff
generic

Capgo SSO Provider Authentication Bypass via PostgREST Direct Write | Advisories | VulnCheck

https://www.vulncheck.com/advisories/capgo-sso-provider-authentication-bypass-via-postgrest-direct-write

Vendor Advisories for CVE-2026-88864(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 52× in last 7d / 78× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-20 02:15 UTCGHSA enrichment
  2. 2026-09-19 22:10 UTCGHSA enrichment
  3. 2026-09-19 18:06 UTCEG score recompute
  4. 2026-09-19 18:06 UTCGHSA enrichment
  5. 2026-09-19 14:01 UTCGHSA enrichment
  6. 2026-09-19 09:44 UTCGHSA enrichment
  7. 2026-09-19 05:27 UTCGHSA enrichment
  8. 2026-09-19 01:23 UTCGHSA enrichment
  9. 2026-09-18 21:19 UTCEG score recompute
  10. 2026-09-18 21:19 UTCGHSA enrichment
  11. 2026-09-18 19:28 UTCEPSS rescore
  12. 2026-09-18 16:16 UTCGHSA enrichment
  13. 2026-09-18 12:11 UTCGHSA enrichment
  14. 2026-09-18 08:07 UTCGHSA enrichment
  15. 2026-09-18 04:03 UTCGHSA enrichment
  16. 2026-09-17 23:59 UTCGHSA enrichment
  17. 2026-09-17 19:54 UTCEG score recompute
  18. 2026-09-17 19:54 UTCGHSA enrichment
  19. 2026-09-17 19:32 UTCEPSS rescore
  20. 2026-09-17 12:17 UTCGHSA enrichment
  21. 2026-09-17 08:12 UTCGHSA enrichment
  22. 2026-09-17 04:08 UTCGHSA enrichment
  23. 2026-09-17 00:04 UTCGHSA enrichment
  24. 2026-09-16 19:59 UTCGHSA enrichment
  25. 2026-09-16 15:41 UTCEG score recompute
Show 53 more
  1. 2026-09-16 15:41 UTCGHSA enrichment
  2. 2026-09-16 14:09 UTCEPSS rescore
  3. 2026-09-16 11:36 UTCGHSA enrichment
  4. 2026-09-16 07:27 UTCEG score recompute
  5. 2026-09-16 07:27 UTCGHSA enrichment
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-16 03:23 UTCGHSA enrichment
  8. 2026-09-15 23:18 UTCGHSA enrichment
  9. 2026-09-15 18:50 UTCGHSA enrichment
  10. 2026-09-15 14:46 UTCGHSA enrichment
  11. 2026-09-15 10:41 UTCGHSA enrichment
  12. 2026-09-15 06:35 UTCEG score recompute
  13. 2026-09-15 06:35 UTCGHSA enrichment
  14. 2026-09-15 03:12 UTCEPSS rescore
  15. 2026-09-15 02:30 UTCGHSA enrichment
  16. 2026-09-14 22:23 UTCGHSA enrichment
  17. 2026-09-14 18:15 UTCGHSA enrichment
  18. 2026-09-14 13:18 UTCGHSA enrichment
  19. 2026-09-14 09:14 UTCGHSA enrichment
  20. 2026-09-14 05:10 UTCGHSA enrichment
  21. 2026-09-14 01:06 UTCGHSA enrichment
  22. 2026-09-13 21:02 UTCGHSA enrichment
  23. 2026-09-13 16:58 UTCEG score recompute
  24. 2026-09-13 16:58 UTCGHSA enrichment
  25. 2026-09-13 16:48 UTCEPSS rescore
  26. 2026-09-13 12:54 UTCGHSA enrichment
  27. 2026-09-13 08:50 UTCGHSA enrichment
  28. 2026-09-13 04:46 UTCGHSA enrichment
  29. 2026-09-13 00:42 UTCGHSA enrichment
  30. 2026-09-12 20:38 UTCGHSA enrichment
  31. 2026-09-12 16:34 UTCEG score recompute
  32. 2026-09-12 16:34 UTCGHSA enrichment
  33. 2026-09-12 15:02 UTCEPSS rescore
  34. 2026-09-12 12:30 UTCGHSA enrichment
  35. 2026-09-12 08:25 UTCGHSA enrichment
  36. 2026-09-12 04:21 UTCGHSA enrichment
  37. 2026-09-12 00:16 UTCGHSA enrichment
  38. 2026-09-11 20:12 UTCGHSA enrichment
  39. 2026-09-11 16:07 UTCEG score recompute
  40. 2026-09-11 16:07 UTCGHSA enrichment
  41. 2026-09-11 14:53 UTCEPSS rescore
  42. 2026-09-11 14:53 UTCEPSS rescore
  43. 2026-09-11 12:00 UTCGHSA enrichment
  44. 2026-09-11 07:56 UTCGHSA enrichment
  45. 2026-09-11 03:52 UTCGHSA enrichment
  46. 2026-09-10 23:48 UTCGHSA enrichment
  47. 2026-09-10 19:25 UTCEG score recompute
  48. 2026-09-10 19:25 UTCGHSA enrichment
  49. 2026-09-10 15:17 UTCEG score recompute
  50. 2026-09-10 15:00 UTCEG score recompute
  51. 2026-09-10 14:20 UTCEG score recompute
  52. 2026-09-10 13:20 UTCEG score recompute
  53. 2026-09-10 13:20 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88864?
CVE-2026-88864 is a critical vulnerability published on September 10, 2026. Capgo (capgo.app) fails to restrict direct write access to the public.ssoproviders table exposed through Supabase PostgREST. A holder of an ordinary Capgo full API key can insert a row with status='active' and enforcesso=true, bypassing the intended backend SSO provisioning route…
When was CVE-2026-88864 disclosed?
CVE-2026-88864 was first published in the National Vulnerability Database on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88864 actively exploited?
CVE-2026-88864 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.4% of all scored CVEs.
What is the CVSS score of CVE-2026-88864?
CVE-2026-88864 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-88864?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-88864, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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