CVE-2026-90474

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreHIGH confidence

Score 6.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-12. the CNA's CVSS baseline 6.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this weekElevated
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.8Exploit: Elevated riskExposed: 0

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

MCPHub before 1.0.32 contains an authentication bypass vulnerability in its embedded OAuth 2.0 authorization server where client authentication is disabled by default and PKCE enforcement is optional. Attackers who obtain an authorization code through interception can redeem it for access tokens without providing a client secret or PKCE verifier, gaining access to victim accounts and their privileges.

CVSS v3
6.8
EG Score
6.8(high)
EG Risk
47(Track*)
EG Risk 47/100SSVC: 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
Severity68% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
1%
EPSS %ILE
44%
KEV
Not listed

Published

September 12, 2026

Last Modified

September 24, 2026

Advisory Details (5)

Auto-updated Sep 12, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
generic

MCPHub before 1.0.32 OAuth 2.0 Authentication Bypass | Advisories | VulnCheck

https://www.vulncheck.com/advisories/mcphub-before-1.0.32-oauth-2.0-authentication-bypass
github Patch Available🟡 PoC Available

OAuth Authorization Server: Client Authentication Not Enforced (No PKCE, `plain` Accepted, Client Secret Skipped) — Intercepted Codes Redeemable Without Secret/Verifier · Advisory · samanhappy/mcphub · GitHub

https://github.com/samanhappy/mcphub/security/advisories/GHSA-3m7m-37xf-xp9x
github_release Patch Available

v1.0.32

Patch available: samanhappy/mcphub v1.0.32

https://github.com/samanhappy/mcphub/releases/tag/v1.0.32
github_commit Patch Available

commit e927620cd1a8 (samanhappy/mcphub)

Patch available: samanhappy/mcphub v1.0.32 (contains commit e927620cd1a8)

https://github.com/samanhappy/mcphub/commit/e927620cd1a80e8691213b01eb8cd6ffa1a66e9f
generic

mcphub/src/services/oauthServerService.ts at v1.0.31 · samanhappy/mcphub · GitHub

https://github.com/samanhappy/mcphub/blob/v1.0.31/src/services/oauthServerService.ts#L26-L38

Vendor Advisories for CVE-2026-90474(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 19× in last 7d / 41× 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. 2026-09-24 14:53 UTCEG score recompute
  2. 2026-09-24 14:53 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-23 17:22 UTCGHSA enrichment
  6. 2026-09-23 13:01 UTCEG score recompute
  7. 2026-09-23 13:01 UTCGHSA enrichment
  8. 2026-09-22 16:01 UTCEPSS rescore
  9. 2026-09-22 14:08 UTCEG score recompute
  10. 2026-09-22 14:08 UTCGHSA enrichment
  11. 2026-09-21 21:09 UTCEPSS rescore
  12. 2026-09-21 15:15 UTCEG score recompute
  13. 2026-09-21 15:15 UTCGHSA enrichment
  14. 2026-09-20 20:16 UTCEPSS rescore
  15. 2026-09-20 16:23 UTCGHSA enrichment
  16. 2026-09-19 17:28 UTCEG score recompute
  17. 2026-09-19 17:28 UTCGHSA enrichment
  18. 2026-09-18 19:28 UTCEPSS rescore
  19. 2026-09-18 18:35 UTCGHSA enrichment
  20. 2026-09-17 19:36 UTCEG score recompute
  21. 2026-09-17 19:36 UTCGHSA enrichment
  22. 2026-09-17 19:32 UTCEPSS rescore
  23. 2026-09-16 17:58 UTCEG score recompute
  24. 2026-09-16 17:58 UTCGHSA enrichment
  25. 2026-09-16 14:09 UTCEPSS rescore
Show 16 more
  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-15 17:33 UTCEG score recompute
  3. 2026-09-15 17:33 UTCGHSA enrichment
  4. 2026-09-15 17:04 UTCEG score recompute
  5. 2026-09-15 17:03 UTCGHSA enrichment
  6. 2026-09-15 08:02 UTCEG score recompute
  7. 2026-09-15 08:02 UTCGHSA enrichment
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-14 09:09 UTCEG score recompute
  10. 2026-09-14 09:09 UTCGHSA enrichment
  11. 2026-09-13 16:48 UTCEPSS rescore
  12. 2026-09-13 10:17 UTCEG score recompute
  13. 2026-09-13 10:17 UTCGHSA enrichment
  14. 2026-09-12 11:24 UTCEG score recompute
  15. 2026-09-12 11:14 UTCEG score recompute
  16. 2026-09-12 11:13 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-90474?
CVE-2026-90474 is a medium vulnerability published on September 12, 2026. MCPHub before 1.0.32 contains an authentication bypass vulnerability in its embedded OAuth 2.0 authorization server where client authentication is disabled by default and PKCE enforcement is optional. Attackers who obtain an authorization code through interception can redeem it for access tokens…
When was CVE-2026-90474 disclosed?
CVE-2026-90474 was first published in the National Vulnerability Database on September 12, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90474 actively exploited?
CVE-2026-90474 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 56.2% of all scored CVEs.
What is the CVSS score of CVE-2026-90474?
CVE-2026-90474 has a CVSS v4.0 base score of 6.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-90474?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90474, 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

Explore the affected products and dependency analysis for CVE-2026-90474

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