PT-2026-48541 · Go · Github.Com/Juev/Nebula-Mesh

Published

2026-06-10

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Updated

2026-06-10

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CVE-2026-48058

CVSS v4.0

4.6

Medium

VectorAV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U
internal/web/session.go and internal/web/oidc.go set HttpOnly and SameSite=Lax on every cookie but never Secure. A single plaintext request to the origin (operator on a LAN, mistyped URL, HTTP→HTTPS not strictly enforced, reverse proxy misconfiguration) discloses the session.

Affected

All released versions up to v0.3.1.

Impact

An attacker who can observe one HTTP request to the origin recovers the session cookie and impersonates the operator for the remainder of its 24h TTL. The OIDC state cookie has a narrower 10-minute window but enables CSRF on the OIDC callback during that window.

Cookie sites

  • internal/web/session.go — Login, StartAuthenticatedSession, CompleteTwoFactor, Logout
  • internal/web/oidc.go — HandleLogin (state set), HandleCallback (state clear)

Suggested fix

Driven by an explicit cookie secure config option, inferred true when tls cert+tls key are configured and false otherwise. rate limit.trust proxy header is deliberately not used as a signal — that flag controls XFF parsing for rate-limit IPs and does not promise the proxy speaks TLS to clients. Operator behind a TLS-terminating proxy sets cookie secure: true explicitly.
Logout and OIDC state-clear cookies also pick up matching HttpOnly + SameSite=Lax so browsers reliably replace the original.

Reproducer

Start nebula-mgmt without tls cert/tls key (the documented "behind a reverse proxy" deployment). Hit any login flow over the local listener:
curl -i -X POST -d 'username=admin&password=…' http://127.0.0.1:8080/ui/login
The Set-Cookie: nebula session=… line will lack Secure. A subsequent unencrypted hop reveals the cookie verbatim.

Operational migration

Operators flipping cookie secure on a running deployment should expect a one-time logout: existing browser cookies have the old attribute set and the new delete-cookie won't match.

Fix

Weakness Enumeration

CWE-614

Related Identifiers

CVE-2026-48058
GHSA-RQFJ-VV8R-XHQC

Affected Products

Github.Com/Juev/Nebula-Mesh