nebula-mesh: Unauthenticated OIDC login endpoint allocates unbounded in-memory state entries without rate limiting

Exploitation

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

CVSS

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

EPSS

• CVE-2026-55512: 0.60% estimated exploitation activity in the next 30 days; percentile 48.61 (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 When OIDC is enabled, GET /ui/oidc/login is reachable without authentication and is registered outside the Web UI rate-limited auth routes. Every request creates a fresh random OIDC state value and stores it in an in-memory map for 10m. Expired states are swept lazily, but there is no rate limit or maximum live-state cap on the allocation path. An unauthenticated remote client can therefore grow OIDC.states for the full state TTL, bounded by request throughput rather than by configured auth rate limits. Details The OIDC login route is registered directly by WithOIDC: - internal/web/web.go:153 registers w.router.Get("/ui/oidc/login", o.HandleLogin). - internal/web/web.go:154 rate-limits only GET /ui/oidc/callback with w.rateLimitMiddleware("auth"). The normal /ui/ route group applies rate limiting to login/register form submissions, but this direct registration happens outside that group: - internal/web/web.go:287 through internal/web/web.go:292 show the rate-limited local…

Published by the source

14 Jul 2026, 20:19 UTC

Last modified by the source

14 Jul 2026, 20:19 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m3cx-mwpg-32jg

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-55512

Advisory: nebula-mesh: Unauthenticated OIDC login endpoint allocates unbounded in-memory state entries without rate limiting
IDs: CVE-2026-55512, GHSA-m3cx-mwpg-32jg
Record: https://patchnext.com/advisories/cve-2026-55512 (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: Medium (CVSS 5.3)
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 0.5.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/forgekeep/nebula-mesh: affected >= 0.2.0, < 0.5.0; fixed in 0.5.0

## 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-m3cx-mwpg-32jg (GitHub-reviewed advisory GHSA-m3cx-mwpg-32jg lists affected ranges: Go github.com/forgekeep/nebula-mesh >=0.2.0 <0.5.0)

Commands are suggestions: review each one before running it.