CVE-2026-53604 nebula-mesh: CA private key not zeroized on web mobile-bundle error paths
An attacker with memory access can recover the CA private key from the heap, allowing them to mint arbitrary host certificates for the mesh network.
- 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-2026-53604?
CVE-2026-53604 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 0.3.8, the web handler renderMobileBundle passes the real *pki.CAResolver directly into mobilebundle.Build. Inside Build, resolver.LoadByID decrypts the CA's ed25519 private key into a *pki.CAManager, but Build never calls CAManager.Wipe() on any return path. As a result, when a mobile-bundle request goes through the web UI and Build returns — especially on error (missing network, invalid prefix, DB error, signing failure) — the plaintext CA private key remains on the Go heap, unwiped, until garbage collection. An attacker able to read process memory (core dump, swap, memory-scraping) can recover the CA signing key, which would allow minting arbitrary host certificates for the mesh. The API handler already does this correctly: it loads the CAManager, defer caMgr.Wipe(), and wraps it in caManagerResolver. Only the web path is affected. This issue has been patched in version 0.3.8.
Which versions are affected by CVE-2026-53604?
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 | 0.3.8 |
github.com/forgekeep/nebula-mesh Go | All versions | 0.3.8 |
github.com/forgekeep/nebula-mesh Go | All versions | 0.3.8 |
How do I fix CVE-2026-53604?
Upgrade github.com/forgekeep/nebula-mesh to 0.3.8 or later.
Is CVE-2026-53604 being exploited?
There is no known exploitation of CVE-2026-53604 in the wild and no public exploit code.
Sources
Also known as GHSA-2p2f-px33-4vv5, GO-2026-5984.