Vulnerability · Published Sep 4, 2026 · Assigned by GitHub_M
CVE-2026-53603nebula-mesh: Operator session tokens stored in plaintext in the database
High 7.1
In plain English
A high-severity security flaw in nebula-mesh from forgekeep. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% 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. Prior to version 0.3.8, Operator session tokens are stored in plaintext in the operator_sessions table (the token column is the PRIMARY KEY). The session token is a 32-byte random hex value sent directly in a cookie and valid for 24 hours. Anyone who can read the database (backup, snapshot, file copy, or SQL-level disclosure) obtains every active session token and can hijack operator sessions directly, with no further authentication. This issue has been patched in version 0.3.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/forgekeep/nebula-mesh | 0.3.8 | GHSA-q4vm-pq3q-8wgq |
| Go | github.com/forgekeep/nebula-mesh | 0.3.8 | GO-2026-5991 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| forgekeep | nebula-mesh | < 0.3.8 |
Weakness: CWE-312, CWE-522 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N