CVE-2026-63464

HIGHPre-NVD 7.77.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% 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
Elevated
7.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.7Exploit: Elevated riskExposed: 0

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

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.6.0 to before version 0.7.2, non-admin operators (role user) can set allow_private: true on their own managed webhook subscription (POST/PATCH /api/v1/webhook-subscriptions). No admin check exists on this field. At delivery time, allow_private switches the dispatcher to an unguarded HTTP client, bypassing the private/loopback/link-local SSRF guard — letting a low-privilege operator make the server request internal addresses. This issue has been patched in version 0.7.2.

CVSS v3
7.7
EG Score
7.7(medium)
EG Risk
51(Track)
EG Risk 51/100SSVC: 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
Severity77% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 4, 2026

Last Modified

September 8, 2026

Advisory Details (3)

Auto-updated Sep 4, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

v0.7.2

Patch available: forgekeep/nebula-mesh v0.7.2

https://github.com/forgekeep/nebula-mesh/releases/tag/v0.7.2
github_commit

commit f3c54530e388 (forgekeep/nebula-mesh)

Fix landed in forgekeep/nebula-mesh commit f3c54530e388 — awaiting tagged release

https://github.com/forgekeep/nebula-mesh/commit/f3c54530e388dd21763e548923426e60a8e93ff0
github Patch Available🟡 PoC Available

Nebula-mesh allows non-admin operators to disable webhook SSRF protection via `allow_private` · Advisory · forgekeep/nebula-mesh · GitHub

https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-7rx3-5wx3-5v76

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/forgekeep/nebula-mesh—0.7.2—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 25× 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. 2026-09-19 05:45 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:22 UTCEG score recompute
  4. 2026-09-16 20:08 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 09:00 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 09:13 UTCEG score recompute
  9. 2026-09-13 23:46 UTCEG score recompute
  10. 2026-09-13 01:32 UTCEG score recompute
  11. 2026-09-11 16:08 UTCEG score recompute
  12. 2026-09-11 14:53 UTCEPSS rescore
  13. 2026-09-11 09:37 UTCEPSS rescore
  14. 2026-09-10 17:42 UTCEG score recompute
  15. 2026-09-09 08:18 UTCEG score recompute
  16. 2026-09-08 22:01 UTCEPSS rescore
  17. 2026-09-08 19:56 UTCEG score recompute
  18. 2026-09-08 18:15 UTCEG score recompute
  19. 2026-09-06 16:54 UTCEG score recompute
  20. 2026-09-06 13:47 UTCEPSS rescore
  21. 2026-09-05 18:38 UTCEG score recompute
  22. 2026-09-05 15:31 UTCEPSS rescore
  23. 2026-09-04 20:24 UTCEG score recompute
  24. 2026-09-04 19:49 UTCEG score recompute
  25. 2026-09-04 19:49 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63464?
CVE-2026-63464 is a high vulnerability published on September 4, 2026. nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.6.0 to before version 0.7.2, non-admin operators (role user) can set allowprivate: true on their own managed webhook subscription (POST/PATCH /api/v1/webhook-subscriptions). No admin check exists on this field. At…
When was CVE-2026-63464 disclosed?
CVE-2026-63464 was first published in the National Vulnerability Database on September 4, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63464 actively exploited?
CVE-2026-63464 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 81.2% of all scored CVEs.
What is the CVSS score of CVE-2026-63464?
CVE-2026-63464 has a CVSS v3 base score of 7.7 (NVD).
How do I remediate CVE-2026-63464?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63464, 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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