8.7

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

Deferred
Published 16-07-2026Last modified 17-07-2026

Vulnerability summary

CVE-2026-62963 is a high (CVSS 8.7) vulnerability in centrifugal centrifugo. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 44.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.7 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 04-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.52%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 16-07-2026
    PublishedVulnerability first disclosed.
  2. 17-07-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.52%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.52% on 05-10-2026

05-10-202604-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Centrifugal1 product

1 vendor · 1 product

References

4 links