CVE-2026-58250

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-25)

CWE

CWE-476

Published

2026-07-08

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• linuxfoundation:nats-server

References

• 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
• https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67

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