Vulnerability · Published Sep 4, 2026 · Assigned by GitHub_M
CVE-2026-55513nebula-mesh: Web UI host creation ignores configured enrollment token TTL and mints 24-hour bearer enrollment tokens
Medium 5.4
In plain English
A medium-severity security flaw in nebula-mesh from forgekeep. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.3.0 to before version 0.5.0, the nebula-mgmt Web UI host-creation path ignores both the server-wide enrollment_token_ttl security setting and per-network network_config.enrollment_token_ttl overrides. API host creation and token-regeneration paths use the configured TTL resolver, but POST /ui/hosts hardcodes now.Add(24 * time.Hour) for newly minted agent enrollment tokens. In deployments that intentionally reduce enrollment-token lifetime, any authenticated operator who can create a host through the Web UI can still mint a bearer enrollment token valid for about 24 hours. This issue has been patched in version 0.5.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/forgekeep/nebula-mesh | 0.5.0 | GHSA-g4x6-jcvr-9m3g |
| Go | github.com/forgekeep/nebula-mesh | 0.5.0 | GO-2026-5987 |
| Go | github.com/juev/nebula-mesh | no fix listed | GO-2026-5987 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| forgekeep | nebula-mesh | >= 0.3.0, < 0.5.0 |
Weakness: CWE-613 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N