Medium 5.3Published Sep 4, 2026

CVE-2026-55512nebula-mesh: Unauthenticated OIDC login endpoint allocates unbounded in-memory state entries without rate limiting

Updated under an hour ago (2026-10-19 09:10 UTC)

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It affects forgekeep nebula-mesh. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for forgekeep nebula-mesh

Exploited in the last 30 days

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.2.0 to before version 0.5.0, 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. This issue has been patched in version 0.5.0.

CVSS: 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

forgekeep nebula-mesh forgekeep:nebula_mesh (from the name)	from 0.2.0, < 0.5.0	CNA record

References

https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-m3cx-mwpg-32jgx-refsource-confirm
https://github.com/forgekeep/nebula-mesh/commit/bc387086cc0e4b9c1654468b7391af19cacfe367x-refsource-misc
https://github.com/forgekeep/nebula-mesh/releases/tag/v0.5.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.