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.
CVE-2026-62963
HIGHPre-NVD 8.78.7
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.7 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 8.7Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.7
- EG Score
- 8.7(low)
- EPSS
- —
- KEV
- Not listed
Published
July 16, 2026
Last Modified
July 16, 2026
Advisory Details (4)
Auto-updated Jul 16, 2026Patch available. Sources: github, github_commit, github_pr, github_release.
github Patch Available
Decompression bomb DoS via permessage-deflate in unidirectional WebSocket transport · Advisory · centrifugal/centrifugo · GitHub
https://github.com/centrifugal/centrifugo/security/advisories/GHSA-q6mr-3g59-5m8xgithub_release Patch Available
v6.8.4
Patch available: centrifugal/centrifugo v6.8.4
https://github.com/centrifugal/centrifugo/releases/tag/v6.8.4github_pr
Bound default decompressed WebSocket message size, options to tweak the limit
Fix merged in centrifugal/centrifugo PR #1162 on 2026-06-28 — awaiting tagged release
https://github.com/centrifugal/centrifugo/pull/1162github_commit
commit 46d40e4ac3a5 (centrifugal/centrifugo)
Fix landed in centrifugal/centrifugo commit 46d40e4ac3a5 — awaiting tagged release
https://github.com/centrifugal/centrifugo/commit/46d40e4ac3a5446c9745f8b219197166ae12a6e5Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-16 19:45 UTCEG score recompute
- 2026-07-16 19:44 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-62963?
CVE-2026-62963 is a high vulnerability published on July 16, 2026. Centrifugo is an open-source scalable real-time messaging server. Prior to 6.8.4, Centrifugo unidirectional WebSocket transport with uniwebsocket.compression enabled enforced uniwebsocket.messagesizelimit against compressed wire-frame length in internal/websocket/conn.go advanceFrame, but…
When was CVE-2026-62963 disclosed?
CVE-2026-62963 was first published in the National Vulnerability Database on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-62963?
CVE-2026-62963 has a CVSS v3 base score of 8.7 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-62963?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-62963, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-62963
Is Your Infrastructure Affected by CVE-2026-62963?
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