Vulnerability · Published Jul 16, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity security flaw in centrifugo from centrifugal. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.5%top 55.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
centrifugal	centrifugo	< 6.8.4

Weakness: CWE-409 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

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