CVE-2026-47723: nebula-mesh Web UI And API Responses Vulnerability

HIGH
Advisory Identifier: GHSA-w7w5-5gcp-38rw
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CWE-1021
Published
Advisory Summary

CVE-2026-47723 is a HIGH web ui and api responses vulnerability (CWE-1021: Improper Restriction of Rendered UI Layers or Frames) affecting nebula-mesh libraries in the Go ecosystem. The issue involves web ui and api responses lack security headers (csp, x-frame-options, hsts, etc.). Remediation is available by upgrading affected packages to version 0.3.1.

CVE-2026-47723 at a Glance

CVE Identifier CVE-2026-47723
GHSA Identifier GHSA-w7w5-5gcp-38rw
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-1021: Improper Restriction of Rendered UI Layers or Frames
Affected Product nebula-mesh
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2026-47723

To remediate this vulnerability, upgrade all affected nebula-mesh dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/juev/nebula-mesh fixed: 0.3.1 
Upgrade github.com/juev/nebula-mesh to 0.3.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/juev/nebula-mesh

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-47723, inspect your project dependencies for nebula-mesh:

inspect dependencies for github.com/juev/nebula-mesh

Analyze the terminal output to locate any version of nebula-mesh in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1021: Improper Restriction of Rendered UI Layers or Frames, where the web application does not restrict or incorrectly restricts frame objects or ui layers that belong to another application or domain. In nebula-mesh, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

None of the response paths in `internal/web/` or `internal/api/` set the standard browser-security headers. `grep` for `Content-Security-Policy`, `X-Frame-Options`, `Strict-Transport-Security`, `X-Content-Type-Options`, `Referrer-Policy` returns zero matches across the codebase. ## Impact The admin UI signs CA certificates, mints API keys (returned inline once per page), displays TOTP QR codes, and exposes operator-management forms. Missing `X-Frame-Options: DENY` / `frame-ancestors 'none'` is a real clickjacking lever against an admin browsing `/ui/operators/*` or `/ui/cas/*`. Missing `X-Content-Type-Options: nosniff` allows MIME confusion on any user-supplied content surface. Missing HSTS on TLS deployments leaves a downgrade window. ## Affected All released versions up to v0.3.0. ## Suggested fix A single response-header middleware mounted at the chi router root in both `/ui/*` and `/api/*` paths: ```go func securityHeadersMiddleware(next http.Handler) http.Handler { return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { h := rw.Header() h.Set("Content-Security-Policy", "default-src 'self'; frame-ancestors 'none'; base-uri 'none'; form-action 'self'") h.Set("X-Content-Type-Options", "nosniff") h.Set("Referrer-Policy", "same-origin") h.Set("X-Frame-Options", "DENY") // belt-and-braces; CSP frame-ancestors is the modern path if r.TLS != nil { h.Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains") } next.ServeHTTP(rw, r) }) } ``` The inline `<script>` in `layout.html` for CSRF wiring (added in the CSRF advisory) will need either a nonce, a hash in CSP, or external-file extraction. Easiest path: a nonce per request (`crypto/rand`, base64) injected into both the CSP header and the script's `nonce=""` attribute.

CVE-2026-47723 Affected nebula-mesh Versions

1 component(s)
Fixed Versions:
0.3.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/juev/nebula-mesh
golang/github.com/juev/nebula-mesh
Go
< 0.3.1
0.3.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/juev/nebula-mesh/security/advisories/GHSA-w7w5-5gcp-38rw
Security Fix Commit FIX COMMIT
https://github.com/forgekeep/nebula-mesh/commit/b45fda5476c41ffcff1ca23058aef0fb851359c1
nebula-mesh Release RELEASE
https://github.com/forgekeep/nebula-mesh/releases/tag/v0.3.1
nebula-mesh Source Repository REPOSITORY
https://github.com/juev/nebula-mesh

Frequently Asked Questions

What is CVE-2026-47723?
CVE-2026-47723 is a security vulnerability in nebula-mesh involving Web UI and API responses lack security headers (CSP, X-Frame-Options, HSTS, etc.) under CWE-1021: Improper Restriction of Rendered UI Layers or Frames.
Which nebula-mesh versions are affected?
Affected versions include releases prior to 0.3.1 across affected packages: github.com/juev/nebula-mesh.
What version fixes CVE-2026-47723?
Upgrading to 0.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/juev/nebula-mesh affected?
Yes, github.com/juev/nebula-mesh is affected in releases prior to 0.3.1. Upgrade your dependency to 0.3.1 or later.
What CWE is associated with CVE-2026-47723?
CVE-2026-47723 is classified under CWE-1021: Improper Restriction of Rendered UI Layers or Frames (The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.).
How can I check Go dependencies for CVE-2026-47723?
Run the dependency tree command: 'inspect dependencies for github.com/juev/nebula-mesh'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w7w5-5gcp-38rw",
  "modified" : "2026-06-08T23:08:54Z",
  "published" : "2026-06-08T23:08:54Z",
  "aliases" : [ "CVE-2026-47723" ],
  "summary" : "nebula-mesh: Web UI and API responses lack security headers (CSP, X-Frame-Options, HSTS, etc.)",
  "details" : "None of the response paths in `internal/web/` or `internal/api/` set the standard browser-security headers. `grep` for `Content-Security-Policy`, `X-Frame-Options`, `Strict-Transport-Security`, `X-Content-Type-Options`, `Referrer-Policy` returns zero matches across the codebase.\n\n## Impact\nThe admin UI signs CA certificates, mints API keys (returned inline once per page), displays TOTP QR codes, and exposes operator-management forms. Missing `X-Frame-Options: DENY` / `frame-ancestors 'none'` is a real clickjacking lever against an admin browsing `/ui/operators/*` or `/ui/cas/*`. Missing `X-Content-Type-Options: nosniff` allows MIME confusion on any user-supplied content surface. Missing HSTS on TLS deployments leaves a downgrade window.\n\n## Affected\nAll released versions up to v0.3.0.\n\n## Suggested fix\nA single response-header middleware mounted at the chi router root in both `/ui/*` and `/api/*` paths:\n\n```go\nfunc securityHeadersMiddleware(next http.Handler) http.Handler {\n    return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {\n        h := rw.Header()\n        h.Set(\"Content-Security-Policy\",\n            \"default-src 'self'; frame-ancestors 'none'; base-uri 'none'; form-action 'self'\")\n        h.Set(\"X-Content-Type-Options\", \"nosniff\")\n        h.Set(\"Referrer-Policy\", \"same-origin\")\n        h.Set(\"X-Frame-Options\", \"DENY\")  // belt-and-braces; CSP frame-ancestors is the modern path\n        if r.TLS != nil {\n            h.Set(\"Strict-Transport-Security\", \"max-age=31536000; includeSubDomains\")\n        }\n        next.ServeHTTP(rw, r)\n    })\n}\n```\n\nThe inline `<script>` in `layout.html` for CSRF wiring (added in the CSRF advisory) will need either a nonce, a hash in CSP, or external-file extraction. Easiest path: a nonce per request (`crypto/rand`, base64) injected into both the CSP header and the script's `nonce=\"\"` attribute.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/juev/nebula-mesh"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.3.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/juev/nebula-mesh/security/advisories/GHSA-w7w5-5gcp-38rw"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/forgekeep/nebula-mesh/commit/b45fda5476c41ffcff1ca23058aef0fb851359c1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/forgekeep/nebula-mesh/releases/tag/v0.3.1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/juev/nebula-mesh"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1021" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-08T23:08:54Z",
    "nvd_published_at" : null
  }
}