# 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.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 8 Sep 2026
- **Also known as:** GHSA-cm26-5974-52h8, GO-2026-5986

## 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.

Weakness: CWE-672 (Operation on a Resource after Expiration or Release), CWE-299 (Improper Check for Certificate Revocation)

## Which versions are affected by CVE-2026-61699?

3 open source packages ship an affected version, including github.com/forgekeep/nebula-mesh.


| Package | Ecosystem | 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61699 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61699 exists.

Affected packages and fixed versions:
- github.com/forgekeep/nebula-mesh (Go): affected all versions; fixed in 0.7.1
- github.com/forgekeep/nebula-mesh (Go): affected all versions; fixed in 0.7.1
- github.com/forgekeep/nebula-mesh (Go): affected all versions; fixed in 0.7.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-61699/ (Markdown: https://insights.sbomify.com/CVE-2026-61699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61699
- OSV: https://osv.dev/vulnerability/CVE-2026-61699

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61699/
Summaries are generated and may contain mistakes; the official description above is the record.