https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-09-30T18:11:36.751419+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/fkie_cve-2026-61699 fkie_cve-2026-61699 2026-09-30T18:11:37.133932+00:00

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.

 https://vulnerability.circl.lu/vuln/ghsa-cm26-5974-52h8 GHSA-cm26-5974-52h8 — nebula-mesh: Certificate revocation is never enforced at the mesh 2026-09-30T18:11:37.134032+00:00

Affected: Go: github.com/forgekeep/nebula-mesh

### 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 `has_updates=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`) and `GeneratorInput` carries no blocklist (`internal/configgen/generator.go:23-52`). So even the server-rendered `config.yml` shipped via `ConfigYAML` cannot carry it.

Result: a blocked/offboarded/compromised host's certificate is never rejected by its peers. Its handshakes keep succeeding for the full remaining cert lifetime — up to 30 days for agent hosts (`DefaultAgentCertDuration`) and 365 days for mobile hosts (`DefaultMobileCertDuration`). Blo…