Vulnerability Description
nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. Prior to version 0.7.1, revocation is the only in-band mechanism that isolates a compromised/offboarded host from a Nebula mesh. Because the blocklist never reaches any peer's config.yml, a Blocked host retains full overlay reachability to every peer under its CA (and internal services on the mesh) for up to 30d (agent) / 365d (mobile). An attacker who exfiltrates host.key+host.crt can run stock slackhq/nebula directly, ignore the agent's 403/410 poll responses, and stay connected after the operator revokes the host. Operator-visible state (UI shows blocked, audit log records it) is misleading. This issue has been patched in version 0.7.1.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/forgekeep/nebula-mesh/commit/0426e2f224a9b1e2029029bf923c93ed
- https://github.com/forgekeep/nebula-mesh/releases/tag/v0.7.1
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-cm26-5974-52h8
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-cm26-5974-52h8
FAQ
What is CVE-2026-61699?
CVE-2026-61699 is a vulnerability with a CVSS score of 8.1 (HIGH). nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. Prior to version 0.7.1, revocation is the only in-band mechanism that isolates a compromised/offboarded host from a Nebula mesh. B...
How severe is CVE-2026-61699?
CVE-2026-61699 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-61699?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.