Vulnerability in github.com/juev/nebula-mesh (CVE-2026-49258)
Summary
Vulnerability in github.com/juev/nebula-mesh (CVE-2026-49258). Successful exploitation can lead to full system takeover. Exploitable via POST /ui/hosts/{id}/block.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-49258 has been found in github.com/juev/nebula-mesh.
Attackers can target a specific entry point like POST /ui/hosts/{id}/block over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/juev/nebula-mesh CVE-2026-49258" on the vendor's site.
CVE-2026-49258 (github.com/juev/nebula-mesh) — CWE-639 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /ui/hosts/{id}/block / DELETE /ui/hosts/{id} / handleHostDetail / handleHostBlock
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-639) exists in github.com/juev/nebula-mesh. Attackers reach the vulnerable code path via POST /ui/hosts/{id}/block.
Check the vendor advisory for the affected versions of github.com/juev/nebula-mesh. Attack surface: POST /ui/hosts/{id}/block / DELETE /ui/hosts/{id} / handleHostDetail / handleHostBlock.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /ui/hosts/{id}/block requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/juev/nebula-mesh' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/juev/nebula-mesh' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/juev/nebula-meshを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /ui/hosts/{id}/block' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /ui/hosts/{id}/blockへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against POST /ui/hosts/{id}/block on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com