nebula-mesh: Web UI and API responses lack security headers (CSP, X-Frame-Options, HSTS, etc.)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

nebula-mesh is a self-hosted control plane for Slack Nebula mesh virtual private network. Prior to version 0.3.1, 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. Version 0.3.1 fixes the issue.

Source published

23 Jul 2026 20:17:26 UTC

Source modified

24 Jul 2026 13:54:01 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 7.1 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

nebula-mesh is a self-hosted control plane for Slack Nebula mesh virtual private network. Prior to version 0.3.1, 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. Version 0.3.1 fixes the issue.

Source published

23 Jul 2026 21:17:04 UTC

Source modified

24 Oct 2026 13:10:00 UTC

Observed here

25 Oct 2026 12:17:26 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 7.1 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

Source published

8 Jun 2026 23:08:54 UTC

Source modified

25 Jun 2026 23:11:13 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · HIGH

nebula-mesh: Web UI and API responses lack security headers (CSP, X-Frame-Options, HSTS, etc.) in github.com/juev/nebula-mesh

Source published

25 Jun 2026 22:34:38 UTC

Source modified

25 Jun 2026 23:01:38 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.