CVE-2026-58250
NATS Server: Pre-auth server crash via double INFO in leafnode handshake
- State
- Published
- Severity
- 7.5 High
- Published
- Jul 8, 2026
- Updated
- Jul 9, 2026
- Reserved
- Jun 29, 2026
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
- CWE-476 NULL Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
nats-servernats-io |
|
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67
- https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a
- https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27
- https://github.com/nats-io/nats-server/releases/tag/v2.11.17
- https://github.com/nats-io/nats-server/releases/tag/v2.12.8
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