Is CVE-2026-55512 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-55512 being exploited in the wild.

How severe is CVE-2026-55512?

Medium severity, with a CVSS score of 5.3, published 4 September 2026.

Which products and versions are affected?

Forgekeep Nebula-Mesh >= 0.2.0, = 0.2.0, < 0.5.0, SEMVER:introduced=0.2.0,fixed=0.5.0, SEMVER:introduced=0.4.0,fixed=0.5.0; github.com/juev/nebula-mesh (Go) SEMVER:introduced=0.2.0.

Is there a fix for CVE-2026-55512?

Yes. github.com/forgekeep/nebula-mesh (Go): upgrade to 0.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-55512 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-55512?

Check whether you run Forgekeep Nebula-Mesh, github.com/forgekeep/nebula-mesh (Go) or github.com/juev/nebula-mesh (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55512: forgekeep nebula-mesh resource exhaustion in OIDC login

Q: Is there a fix for CVE-2026-55512?

Yes. github.com/forgekeep/nebula-mesh (Go): upgrade to 0.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-55512 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-55512?

Check whether you run Forgekeep Nebula-Mesh, github.com/forgekeep/nebula-mesh (Go) or github.com/juev/nebula-mesh (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55512 · Severity: medium · CVSS 5.3 · Published 2026-09-04

A vulnerability in the nebula-mesh authentication system allows unauthenticated users to exhaust server memory. By repeatedly accessing the OIDC login page, an attacker can force the server to store large amounts of temporary data that does not expire quickly enough. This can lead to service slowdowns or crashes, impacting the availability of the mesh network management interface.

Technologies: Forgekeep Nebula-Mesh, github.com/forgekeep/nebula-mesh (Go), github.com/juev/nebula-mesh (Go). Vendors: Forgekeep, Go.

Quick answers

Is CVE-2026-55512 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-55512 being exploited in the wild.
How severe is CVE-2026-55512?: Medium severity, with a CVSS score of 5.3, published 4 September 2026.
Which products and versions are affected?: Forgekeep Nebula-Mesh >= 0.2.0, < 0.5.0; github.com/forgekeep/nebula-mesh (Go) >= 0.2.0, < 0.5.0, SEMVER:introduced=0.2.0,fixed=0.5.0, SEMVER:introduced=0.4.0,fixed=0.5.0; github.com/juev/nebula-mesh (Go) SEMVER:introduced=0.2.0.
Is there a fix for CVE-2026-55512?: Yes. github.com/forgekeep/nebula-mesh (Go): upgrade to 0.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55512 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-55512?: Check whether you run Forgekeep Nebula-Mesh, github.com/forgekeep/nebula-mesh (Go) or github.com/juev/nebula-mesh (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/forgekeep/nebula-mesh (Go): upgrade to 0.5.0 or later
```
go get github.com/forgekeep/nebula-mesh@v0.5.0
```

Technical details

An uncontrolled resource consumption vulnerability exists in nebula-mesh when OIDC is enabled. The 'GET /ui/oidc/login' endpoint is registered outside of the standard rate-limiting middleware and does not require authentication. Each request to this endpoint generates a unique OIDC state token stored in an in-memory map with a 10-minute TTL. Because there is no cap on the number of live states or rate limiting on the allocation path, a remote attacker can flood the endpoint to cause linear memory growth. The issue is fixed in version 0.5.0 by applying rate limits and state caps.

Affected products

forgekeep nebula-mesh >= 0.2.0, < 0.5.0

Identifiers

CVE-2026-55512
GHSA-m3cx-mwpg-32jg
GO-2026-5989

Timeline

2026-06-13: disclosed: Initial report by sondt99
2026-07-14: advisory: GitHub Advisory published
2026-07-14: patched: Version 0.5.0 released

References

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