8.1
HIGH CVSS 3.1
CVE-2026-61699
nebula-mesh: Certificate revocation is never enforced at the mesh
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.

INFO

Published Date :

Sept. 4, 2026, 8:17 p.m.

Last Modified :

Sept. 4, 2026, 8:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-61699 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update nebula-mesh to version 0.7.1 or later to fix host authentication and reachability issues.
  • Update nebula-mesh to version 0.7.1 or later.
  • Verify host revocation mechanism functions correctly.
  • Ensure blocklist is updated on all peers.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-61699.

URL Resource
https://github.com/forgekeep/nebula-mesh/commit/0426e2f224a9b1e2029029bf923c93ed39d21cdb
https://github.com/forgekeep/nebula-mesh/releases/tag/v0.7.1
https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-cm26-5974-52h8
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-61699 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-61699 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-61699 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-61699 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 04, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-299
    Added CWE CWE-672
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61699.json">CVE-2026-61699</a>
    Added Reference https://github.com/forgekeep/nebula-mesh/commit/0426e2f224a9b1e2029029bf923c93ed39d21cdb
    Added Reference https://github.com/forgekeep/nebula-mesh/releases/tag/v0.7.1
    Added Reference https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-cm26-5974-52h8
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.