CVE-2026-62963
HighCVSS 8.7Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
In Centrifugo before version 6.8.4, the unidirectional WebSocket transport with compression enabled enforced message size limit before decompression, but after decompression there was no output cap. This allowed unauthenticated requests to /connection/uni_websocket to trigger high memory and CPU consumption.
Risk Assessment
An attacker can send small compressed WebSocket frames that decompress into very large messages, exhausting server resources and potentially causing a denial of service (DoS).
Recommendation
Upgrade Centrifugo to version 6.8.4 or later immediately, which includes a fix that limits message size after decompression.
Other vulnerabilities in Centrifugo
See all- CVE-2026-71485Critical
Centrifugo before version 6.9.0 allows a remote client to spoof headers such as x-trusted-user in connect, refresh, subscribe, publish, RPC, and related proxy calls when the backend relies on that header for authentication or authorization. The vulnerability arises from copying client-controlled headers into the connection context and forwarding them as trusted backend headers.
- CVE-2026-49998High
In Centrifugo before version 6.8.1, dynamic JWKS endpoint verification could reuse a key for one allowed issuer to verify a JWT for another allowed issuer. This occurred because the JWKS cache and singleflight lookup were keyed only by the JWT header kid, not by the resolved JWKS endpoint, issuer, audience, or trust-domain namespace.
Original NVD description (English source)
Centrifugo is an open-source scalable real-time messaging server. Prior to 6.8.4, Centrifugo unidirectional WebSocket transport with uni_websocket.compression enabled enforced uni_websocket.message_size_limit against compressed wire-frame length in internal/websocket/conn.go advanceFrame, but ReadMessage used io.ReadAll after decompression without an output cap, allowing unauthenticated requests to /connection/uni_websocket to trigger large memory and CPU consumption. This issue is fixed in version 6.8.4.