Vulnerability Description
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linuxfoundation | Nats-Server | < 2.11.14 |
Related Weaknesses (CWE)
References
- https://advisories.nats.io/CVE/secnote-2026-04.txtMitigationVendor Advisory
- https://github.com/nats-io/nats-server/commit/a1488de6f2ba6e666aef0f9cce0016f7f1Patch
- https://github.com/nats-io/nats-server/security/advisories/GHSA-52jh-2xxh-pwh6MitigationVendor Advisory
FAQ
What is CVE-2026-29785?
CVE-2026-29785 is a vulnerability with a CVSS score of 7.5 (HIGH). NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not d...
How severe is CVE-2026-29785?
CVE-2026-29785 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-29785?
Check the references section above for vendor advisories and patch information. Affected products include: Linuxfoundation Nats-Server.