# GHSA-ghmh-jhmj-wcmf: nebula-mesh's stores enrollment tokens unhashed in SQLite

> Attackers with local database access can steal unhashed enrollment tokens to hijack agent identities, requiring a patch to hash tokens at rest.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Jun 2026
- **Also known as:** GO-2026-5399

## What is GHSA-ghmh-jhmj-wcmf?

GHSA-ghmh-jhmj-wcmf is a vulnerability in github.com/juev/nebula-mesh, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

`internal/store/sqlite.go:1177,1192,1221,1245` — the `enrollment_tokens.token` column holds the raw UUID token. `ConsumeToken` does `WHERE token = ?` against the raw string. Compare with `operator_api_keys.key_hash`, which is SHA-256 hex (constructed in `internal/api/middleware.go:51-53`).

## Affected
All released versions up to v0.3.0.

## Threat model
Read access to `nebula-mgmt.db`: backup, snapshot, file-system access, future SQL-injection sink. The principle of defense-in-depth: API keys are hashed at rest; enrollment tokens — which grant the same lifecycle authority over a host's identity — are not.

An attacker who reads the DB before a legitimate agent enrolls can consume the single-use token first, mint a cert against their own keypair, and take the agent's intended Nebula identity.

## Suggested fix
1. Schema migration: rename `enrollment_tokens.token` → `token_hash` (or add the new column and drop the old after backfill of pending rows).
2. Store SHA-256 of token on create:
   ```go
   sum := sha256.Sum256([]byte(token))
   row.TokenHash = hex.EncodeToString(sum[:])
   ```
3. `ConsumeToken` accepts the raw token, hashes once, looks up by hash, atomically marks consumed.

Side bonus: take this opportunity to switch the token format from `uuid.New().String()` (122 bits) to `hex.EncodeToString(crypto/rand 32 bytes)` (256 bits), matching the project's session-token and API-key conventions. UUIDs are recognisable in logs and crash dumps; opaque hex blends in.

TOTP recovery codes appear to already be SHA-256 hashed at rest (`internal/web/totp.go:74-78`) — confirming that pattern is intentional elsewhere, just missed here.

## Which versions are affected by GHSA-ghmh-jhmj-wcmf?

3 open source packages ship an affected version, including github.com/juev/nebula-mesh.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/juev/nebula-mesh` | Go | All versions | 0.3.2 |
| `github.com/juev/nebula-mesh` | Go | All versions | 0.3.2 |
| `github.com/juev/nebula-mesh` | Go | All versions | 0.3.2 |

## How do I fix GHSA-ghmh-jhmj-wcmf?

Upgrade github.com/juev/nebula-mesh to 0.3.2 or later.

## Is GHSA-ghmh-jhmj-wcmf being exploited?

There is no known exploitation of GHSA-ghmh-jhmj-wcmf in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-ghmh-jhmj-wcmf and fix it if it is affected.

What it is: GHSA-ghmh-jhmj-wcmf is a vulnerability in github.com/juev/nebula-mesh, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-ghmh-jhmj-wcmf in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/juev/nebula-mesh (Go): affected all versions; fixed in 0.3.2
- github.com/juev/nebula-mesh (Go): affected all versions; fixed in 0.3.2
- github.com/juev/nebula-mesh (Go): affected all versions; fixed in 0.3.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-ghmh-jhmj-wcmf/ (Markdown: https://insights.sbomify.com/GHSA-ghmh-jhmj-wcmf/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-ghmh-jhmj-wcmf

---
From sbomify Insights: https://insights.sbomify.com/GHSA-ghmh-jhmj-wcmf/
Summaries are generated and may contain mistakes; the official description above is the record.