---
cve: "CVE-2026-49258"
severity: "HIGH"
cvss: 8.8
epss: "0.5%"
vendor: "juev"
kev: false
exploited: false
published: "2026-07-28 19:17:36"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-11-02T18:30:44+01:00"
---

# CVE-2026-49258

> 8.8 HIGH · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-07-28 19:21:43
- CNA-CVSS: **8.8** (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-639** — Authorization Bypass Through User-Controlled Key
  The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
- **CWE-862** — Missing Authorization
  The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

## Patch verfügbar (OSV)

- 01fdc54a2bc2e885048636576cab998c6f2c7fe9 (Commit)

## Referenzen

- <https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-c6v2-3ffm-vcmc>
- <https://github.com/forgekeep/nebula-mesh/pull/161>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-49258/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_