CVE-2026-49258
highpriority · track · 0OT risk · elevatedEPSS 0.005 · 41 %ileEUUSEPSS · scored 2026-10-27
Nebula Mesh is a self-hosted control plane for the Slack Nebula mesh VPN. In versions 0.3.5 and below, the web UI (/ui/*) does not apply the per-operator CA scoping employed by the JSON API. This was partially addressed by GHSA-598g-h2vc-h5vg, but the changes were not implemented in the web read/mutation surface. Any authenticated non-admin operator (for example, one created via self-registration or OIDC) can access resources belonging to other operators. The host create/edit/mobile-bundle/network-create paths and all CA-management routes were already correctly scoped. A malicious operator could block or delete any other operator's host, or read any operator's hosts and networks. This issue has been fixed in version 0.3.6.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
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affected products (3)
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advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-c6v2-3ffm-vcmcNebula Mesh: Web UI lacks ownership checks, enabling cross-operator access to hosts and networks (read, block, delete)2026-06-26ghsa · osvUS
## Summary The web UI (`/ui/*`) does not apply the per-operator CA scoping the JSON API received for GHSA-598g-h2vc-h5vg. Any authenticated non-admin operator (for example, one created via self-registration or OIDC) can access resources belonging to other operators. ## Impact A non-admin operator can: - **Block or delete any other operator's host.** `POST /ui/hosts/{id}/block` and `DELETE /ui/hosts/{id}` act on the URL `id` with no ownership check, so a non-admin can block (revoking the host's certificate via the blocklist) or delete any host in the deployment — a cross-operator denial of service. - **Read every operator's hosts and networks.** The dashboard, `/ui/hosts`, the host detail page, `/ui/networks` (including the create-form error re-render), and the `/ui/events` stream all return data across all operators, exposing host names, Nebula IPs, public IPs, certificate fingerprints and expiry, and network names and CIDRs. This is the same cross-operator class as GHSA-598g; that remediation covered the JSON API but not the web read/mutation surface. The host create/edit/mobile-bundle/network-create paths and all CA-management routes were already correctly scoped. Affected handlers (`internal/web`): `handleHostDetail`, `handleHostBlock`, `handleHostDelete`, `handleDashboard`, `handlePartialStats`, `handleHosts`, `handleNetworks`, `renderNetworksError`, `handleHostEvents`. ## Conditions Exposure requires at least one non-admin operator to exist (self-registration enabled, OIDC, or an admin-created user). A single-admin deployment with no additional operators is not affected. ## Fix A complete candidate fix with regression tests is ready in a private repository shared with the maintainer (`ak2k/nebula-mesh-ghsa-web`, PR #1): scope these handlers to the session operator's owned CAs (admins keep the full view), mirroring the API's ownership checks.
- GO-2026-5816Nebula Mesh: Web UI lacks ownership checks, enabling cross-operator access to hosts and networks (read, block, delete) in github.com/juev/nebula-mesh2026-07-07vendor · osvUS
Nebula Mesh: Web UI lacks ownership checks, enabling cross-operator access to hosts and networks (read, block, delete) in github.com/juev/nebula-mesh
also known as (5)
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sources
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references (7)
External citations — patches, advisories, analysis.
- https://github.com/forgekeep/nebula-mesh/pull/161cnnvd
- https://github.com/forgekeep/nebula-mesh/releases/Patchcnnvd
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-c6v2-3ffm-vcmccnnvd
- https://github.com/forgekeep/nebula-mesh/pull/161enisa_euvd
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-c6v2-3ffm-vcmcenisa_euvd
- https://github.com/forgekeep/nebula-mesh/pull/161nvd
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-c6v2-3ffm-vcmcnvd
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