What’s Vulnerable › Vulnerabilities

CVE-2026-62963: Centrifugo: Decompression bomb DoS via permessage-deflate in unidirectional WebSocket transport

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-16 · updated 2026-10-24
• Weakness: CWE-409

Description

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.

Affected products

• centrifugal centrifugo: before 6.8.4

References

• https://github.com/centrifugal/centrifugo/commit/46d40e4ac3a5446c9745f8b219197166ae12a6e5
• https://github.com/centrifugal/centrifugo/pull/1162
• https://github.com/centrifugal/centrifugo/releases/tag/v6.8.4
• https://github.com/centrifugal/centrifugo/security/advisories/GHSA-q6mr-3g59-5m8x

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