CVE-2026-63464

Nebula-mesh allows non-admin operators to disable webhook SSRF protection via `allow_private`

HIGH
7.7
CVSS Score
Published: September 4, 2026 at 07:44 PM UTC
Updated: September 8, 2026 at 09:19 PM UTC
1 product affected across 1 vendorNebula Mesh

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Severity
HIGH7.7
Exploit prediction
EPSS 0.5%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.7.2
Affected range stops below 0.7.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862CWE-918

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