Overview
About vulnerability
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, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.Details
- Affected product:
- Grafana , Loki , MinIO , benmathews/bench , centrifugal/centrifuge , github.com/benmathews/bench , github.com/centrifugal/centrifuge , github.com/go-kit/kit , github.com/grpc-ecosystem/go-grpc-middleware , github.com/hashicorp/raft-wal , github.com/influxdata/telegraf , github.com/nats-io/nats-server , github.com/nats-io/nats-streaming-server , github.com/prometheus/client_golang , github.com/prometheus/common , go-kit/kit , grafana/tempo , grpc-ecosystem/go-grpc-middleware , hashicorp/raft-wal , heroku/x , influxdata/telegraf , nats-io/nats-server , nats-io/nats-streaming-server , prometheus/client_golang , prometheus/common , spf13/cobra , spf13/viper
- Affected packages:
- github.com/nats-io/nats-server @ 2.1.4 (+39 more)