CVE-2026-47427

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 63% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go runtime panic; because the crash occurs before any authentication or token validation, any unauthenticated client able to send JSON-RPC messages can crash the server, resulting in a complete denial of service. This issue is fixed in version 1.1.0.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

July 28, 2026

Last Modified

August 8, 2026

Advisory Details (4)

Auto-updated Jul 28, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_commit, github_pr.
github Patch Available🟡 PoC Available

Nil Pointer Dereference DoS in completion/complete Handler · Advisory · github/github-mcp-server · GitHub

https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7
github_release Patch Available

GitHub MCP Server 1.1.0

Patch available: github/github-mcp-server v1.1.0

https://github.com/github/github-mcp-server/releases/tag/v1.1.0
github_pr

fix: guard CompletionsHandler against nil params/ref

Fix merged in github/github-mcp-server PR #2502 on 2026-05-19 — awaiting tagged release

https://github.com/github/github-mcp-server/pull/2502
github_commit

commit c88d2ecdd3bb (github/github-mcp-server)

Fix landed in github/github-mcp-server commit c88d2ecdd3bb — awaiting tagged release

https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58

Vendor Advisories for CVE-2026-47427(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/github/github-mcp-server—1.1.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 56× 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. 2026-08-26 14:46 UTCEPSS rescore
  2. 2026-08-25 20:11 UTCEG score recompute
  3. 2026-08-25 13:49 UTCEPSS rescore
  4. 2026-08-24 21:58 UTCEG score recompute
  5. 2026-08-24 10:52 UTCEG score recompute
  6. 2026-08-23 01:33 UTCEG score recompute
  7. 2026-08-23 00:19 UTCEPSS rescore
  8. 2026-08-22 03:20 UTCEG score recompute
  9. 2026-08-21 23:49 UTCEPSS rescore
  10. 2026-08-21 05:07 UTCEG score recompute
  11. 2026-08-20 22:55 UTCEPSS rescore
  12. 2026-08-19 19:47 UTCEG score recompute
  13. 2026-08-19 17:04 UTCEPSS rescore
  14. 2026-08-18 18:39 UTCEG score recompute
  15. 2026-08-18 13:48 UTCEPSS rescore
  16. 2026-08-17 19:56 UTCEG score recompute
  17. 2026-08-17 13:47 UTCEPSS rescore
  18. 2026-08-16 20:40 UTCEG score recompute
  19. 2026-08-16 14:56 UTCEPSS rescore
  20. 2026-08-16 09:34 UTCEG score recompute
  21. 2026-08-16 02:14 UTCEPSS rescore
  22. 2026-08-15 11:22 UTCEG score recompute
  23. 2026-08-15 01:30 UTCEPSS rescore
  24. 2026-08-14 02:03 UTCEG score recompute
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 31 more
  1. 2026-08-12 16:45 UTCEG score recompute
  2. 2026-08-12 13:51 UTCEPSS rescore
  3. 2026-08-11 18:25 UTCEG score recompute
  4. 2026-08-11 07:19 UTCEG score recompute
  5. 2026-08-11 00:00 UTCEPSS rescore
  6. 2026-08-09 22:01 UTCEG score recompute
  7. 2026-08-09 13:46 UTCEPSS rescore
  8. 2026-08-08 23:48 UTCEG score recompute
  9. 2026-08-08 16:37 UTCEPSS rescore
  10. 2026-08-07 18:17 UTCEG score recompute
  11. 2026-08-06 20:05 UTCEG score recompute
  12. 2026-08-06 13:47 UTCEPSS rescore
  13. 2026-08-05 21:52 UTCEG score recompute
  14. 2026-08-05 19:17 UTCEPSS rescore
  15. 2026-08-04 23:38 UTCEG score recompute
  16. 2026-08-04 15:10 UTCEPSS rescore
  17. 2026-08-04 12:32 UTCEG score recompute
  18. 2026-08-04 10:39 UTCEPSS rescore
  19. 2026-08-03 13:05 UTCEG score recompute
  20. 2026-08-03 10:36 UTCEPSS rescore
  21. 2026-08-02 03:47 UTCEG score recompute
  22. 2026-08-02 02:27 UTCEPSS rescore
  23. 2026-08-01 05:35 UTCEG score recompute
  24. 2026-08-01 04:16 UTCEPSS rescore
  25. 2026-07-30 20:14 UTCEG score recompute
  26. 2026-07-30 16:28 UTCEPSS rescore
  27. 2026-07-30 15:00 UTCEG score recompute
  28. 2026-07-30 03:50 UTCEG score recompute
  29. 2026-07-30 01:30 UTCEPSS rescore
  30. 2026-07-28 18:26 UTCEG score recompute
  31. 2026-07-28 15:22 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-47427?
CVE-2026-47427 is a high vulnerability published on July 28, 2026. GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go…
When was CVE-2026-47427 disclosed?
CVE-2026-47427 was first published in the National Vulnerability Database on July 28, 2026, with the most recent update on August 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47427 actively exploited?
CVE-2026-47427 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 63.3% of all scored CVEs.
What is the CVSS score of CVE-2026-47427?
CVE-2026-47427 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-47427?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47427, 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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