Answer in brief
CVE-2026-55512 records a Medium severity (CVSS 5.3) vulnerability in nebula-mesh: Unauthenticated OIDC login endpoint allocates unbounded in-memory state entries without rate limiting. The current sources do not mark it as known exploited. The current feed maps forgekeep/nebula-mesh (generic), github.com/forgekeep/nebula-mesh (go), github.com/forgekeep/nebula-mesh (go), github.com/forgekeep/nebula-mesh (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps forgekeep/nebula-mesh (generic), github.com/forgekeep/nebula-mesh (go), github.com/forgekeep/nebula-mesh (go), github.com/forgekeep/nebula-mesh (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| forgekeep/nebula-meshgeneric | >= 0.2.0, < 0.5.0 | Not reported |
| github.com/forgekeep/nebula-meshgo | >=0.2.0,<0.5.0 | 0.5.0 |
| github.com/forgekeep/nebula-meshgo | >=0.4.0 <0.5.0 | 0.5.0 |
| github.com/forgekeep/nebula-meshgo | >=0.2.0 <0.5.0 | 0.5.0 |
| github.com/juev/nebula-meshgo | >=0.2.0 | Not reported |
Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.