CVE-2026-61699 nebula-mesh: Certificate revocation is never enforced at the mesh
Attackers with stolen keys bypass certificate revocation in nebula-mesh, maintaining unauthorized network access despite operator blocking.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-61699?
CVE-2026-61699 is a high-severity vulnerability in forgekeep nebula-mesh, published on 4 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-61699?
3 open source packages ship an affected version, including github.com/forgekeep/nebula-mesh.
| Package | Affected | Fixed in |
|---|---|---|
github.com/forgekeep/nebula-mesh Go | All versions | 0.7.1 |
github.com/forgekeep/nebula-mesh Go | All versions | 0.7.1 |
github.com/forgekeep/nebula-mesh Go | All versions | 0.7.1 |
How do I fix CVE-2026-61699?
Upgrade github.com/forgekeep/nebula-mesh to 0.7.1 or later.
Is CVE-2026-61699 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61699 exists.
Sources
Also known as GHSA-cm26-5974-52h8, GO-2026-5986.