CVE-2026-49258

Status: DeferredHigh (8.8)—

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

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base score: 8.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.48%
Percentile among all scored CVEs: 39
Score date: 10/6/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1210 Exploitation of Remote Serviceslateral movement75 %
Primary impactT1078 Valid Accountsstealth · persistence · privilege escalation · initial access85 %
Secondary impactT1005 Data from Local Systemcollection75 %
Secondary impactT1565.001 Stored Data Manipulationimpact70 %

Acceso remoto con credenciales válidas (PR:L) permite a operador no-admin eludir scoping de CA en web UI, accediendo/modificando recursos de otros operadores y leyendo hosts y redes.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Application Developer Guidance Active Directory Configuration Vulnerability Scanning User Training User Account Management

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Slack — Nebula Mesh^AI

CWEs

CWE-639, CWE-862

References

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-49258",
  "cveTags": [],
  "metrics": {
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          "options": [
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              "exploitation": "none"
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              "automatable": "no"
            },
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              "technicalImpact": "total"
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          "version": "2.0.3",
          "timestamp": "2026-07-28T19:21:26.834734Z"
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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          "userInteraction": "NONE",
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  "published": "2026-07-28T19:17:36.000",
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      "url": "https://github.com/forgekeep/nebula-mesh/pull/161",
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      "value": "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."
    }
  ],
  "lastModified": "2026-07-30T16:41:25.650",
  "sourceIdentifier": "security-advisories@github.com"
}