CVSS 3.1
5.4 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:NCVE-2026-33223
Medium (5.4) in linuxfoundation nats-server. EPSS 0.2% chance of exploitation in the next 30 days. Fixed in github.com/nats-io/nats-server/v2 2.11.15, 2.12.6.
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, the NATS message header `Nats-Request-Info:` is supposed to be a guarantee of identity by the NATS server, but the stripping of this header from inbound messages was not fully effective. An attacker with valid credentials for any regular client interface could thus spoof their identity to services which rely upon this header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 11% of CVEs (scores of 2026-10-31)
- CWE
- CWE-290
- Published
- Modified
- Record from
- the NVD, synced
Affected
- linuxfoundation:nats-server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-pwx7-fx9r-hr4h | Go | github.com/nats-io/nats-server/v2 | <2.11.15 | 2.11.15 |
| GHSA-pwx7-fx9r-hr4h | Go | github.com/nats-io/nats-server/v2 | >=2.12.0-RC.1 <2.12.6 | 2.12.6 |
| GHSA-pwx7-fx9r-hr4h | Go | github.com/nats-io/nats-server | all versions | no fix published |
| GO-2026-4835 | Go | github.com/nats-io/nats-server | all versions | no fix published |
| GO-2026-4835 | Go | github.com/nats-io/nats-server/v2 | <2.11.15 >=2.12.0-RC.1 <2.12.6 | 2.11.15, 2.12.6 |