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CVE-2026-55512

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

Published: Sep 4, 2026Updated: Sep 4, 2026 Sources: CVE List NVDCWE-400
5.3MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 74.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:L
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:LAvailability
Low
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Weaknesses

CWE-400

Affected Products

forgekeep
nebula-mesh

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-m3cx-mwpg-32jg
github.com
https://github.com/forgekeep/nebula-mesh/commit/bc387086cc0e4b9c1654468b7391af19cacfe367
github.com
https://github.com/forgekeep/nebula-mesh/releases/tag/v0.5.0
github.com

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