nebula-mesh: Certificate revocation is never enforced at the mesh

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-61699: 0.45% estimated exploitation activity in the next 30 days; percentile 38.81 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary nebula-mesh revokes a host by adding its certificate fingerprint to a per-CA blocklist and shipping that list to every other agent on each poll. Slack's Nebula enforces certificate revocation ONLY through the pki.blocklist list in config.yml (no CRL/OCSP). The project's own code states this: internal/pki/durations.go:15 — "Revocation via the blocklist remains the immediate security control." The server side is fully implemented (computes per-CA blocklist via GetBlocklistForCA, returns it in the agent-updates response, sets hasupdates=true when non-empty). The agent side was never implemented: 1. The agent decodes the blocklist JSON field into UpdatesResponse.Blocklist (internal/agent/poller.go:33) and then DISCARDS it — poll() applies CertificatePEM, CACertPEM, ConfigYAML, but never references updates.Blocklist (internal/agent/poller.go:300-339). 2. The config generator has NO field to emit pki.blocklist — pkiSection is only ca/cert/key (internal/configgen/marshal.go:42-46)…

Published by the source

14 Jul 2026, 20:28 UTC

Last modified by the source

14 Jul 2026, 20:28 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cm26-5974-52h8

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# Patch Next advisory brief: CVE-2026-61699

Advisory: nebula-mesh: Certificate revocation is never enforced at the mesh
IDs: CVE-2026-61699, GHSA-cm26-5974-52h8
Record: https://patchnext.com/advisories/cve-2026-61699 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/forgekeep/nebula-mesh 0.7.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/forgekeep/nebula-mesh: affected < 0.7.1; fixed in 0.7.1

## Suggested inspection (read-only)
- Go github.com/forgekeep/nebula-mesh: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/forgekeep/nebula-mesh.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cm26-5974-52h8 (GitHub-reviewed advisory GHSA-cm26-5974-52h8 lists affected ranges: Go github.com/forgekeep/nebula-mesh >=0 <0.7.1)

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