Summary
nebula-mesh's web UI lacks CSRF tokens on /ui/* mutating endpoints
Every /ui/* POST / PUT / PATCH / DELETE route processes the request as soon as the session cookie validates. SameSite=Lax on the session cookie prevents most cross-site form submits but does not protect:
- top-level form-submit navigations from third-party pages (some browsers still send Lax cookies on top-level POSTs)
- same-registrable-domain attackers (sibling-subdomain XSS, subdomain takeover)
- the
GET /ui/logoutroute, which a third-party<img src=".../ui/logout">can force-trigger
The admin UI signs CA certificates, mints API keys, rotates / retires / deletes CAs, disables operators, and changes server settings. CSRF here is a real privilege escalation, not just annoyance.
Affected
All released versions up to v0.3.2.
Reproducer
With an authenticated operator session in browser tab A, open the following minimal HTML in any other tab:
<form action="https://nebula.example.com/ui/cas/{ca-id}/delete" method="POST">
<button>Click for free puppy</button>
</form>
Click. The CA is deleted, the server processes the POST because the session cookie is automatically attached and there is no other check. The same trick works for force-rotate, retire, mint API keys, disable operators, etc.
Alternative force-logout: <img src="https://nebula.example.com/ui/logout"> placed on an attacker's page logs out any visiting authenticated operator. No interaction required.
Notes
- Multipart and JSON endpoints don't exist in the current UI surface. Future additions must rely on the header path because
r.PostFormValueonly readsapplication/x-www-form-urlencodedbodies. The middleware's package comment documents this. - The patch assumes nebula-mgmt is the sole authority on its registrable domain. A compromised sibling subdomain can still set parent-domain cookies and forge matches; SameSite=Lax does not prevent that. Documented in the patch.
Impact
The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access. Typical impact: privilege escalation beyond the intended level.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Double-submit cookie: a 32-byte crypto/rand token in a non-HttpOnly _csrf cookie, echoed in either X-CSRF-Token (htmx) or a _csrf form field (HTML forms). Compared in constant time. Rotated on every privilege transition (Login, OIDC StartAuthenticatedSession, CompleteTwoFactor, Logout) so pre-auth fixation cannot survive promotion. Rejections audit-logged as ui.csrf.rejected with reason; response body stays opaque.
/ui/logout becomes POST so it is no longer reachable via <img> tags.
Fix coordinates with the Secure-cookie advisory disclosed concurrently, the _csrf cookie inherits the same Secure-attribute derivation.
Frequently Asked Questions
- What is CVE-2026-47725? CVE-2026-47725 is a high-severity improper privilege management vulnerability in github.com/juev/nebula-mesh (go), affecting versions <= 0.3.2. It is fixed in 0.3.3. The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access.
- Which versions of github.com/juev/nebula-mesh are affected by CVE-2026-47725? github.com/juev/nebula-mesh (go) versions <= 0.3.2 is affected.
- Is there a fix for CVE-2026-47725? Yes. CVE-2026-47725 is fixed in 0.3.3. Upgrade to this version or later.
- Is CVE-2026-47725 exploitable, and should I be worried? Whether CVE-2026-47725 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-47725 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-47725? Upgrade
github.com/juev/nebula-meshto 0.3.3 or later.