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Fencer Vulns
medium 6.3

CVE-2026-54464 json

websocket-driver: Resource limit bypass via message compression

published 2026-07-15 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-45309 , GHSA-33ph-fccm-39pj

cvss
6.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

### Impact

If this library is used in tandem with the `permessage-deflate` extension, a WebSocket server or client can be made to accept messages that are larger than the configured maximum message size. This is because this limit is checked against the message frames' length headers, which give the size of the compressed data, not the size after decompression. This can lead to applications accepting larger messages than expected and exceeding their intended resource usage.

### Patches

The issue has been patched in version 0.8.1, by checking the length of messages after they are processed by incoming extensions. All users should upgrade to this version.

### Workarounds

No known workarounds exist.

### Acknowledgements

This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

Patch / fix

  • rubygems websocket-driver 0.8.1
  • faye websocket-driver 0.8.1
  • ruby-websocket-driver Debian 14 0.8.1-1

debian advisories DEBIAN-CVE-2026-54464

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-54464 updated cvss 5.3

websocket-driver: websocket-driver: Denial of Service due to oversized decompressed WebSocket messages

  • Red Hat 3scale API Management Platform 2 3scale-amp2/zync-rhel9, 3scale-amp2/system-rhel8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat 3scale API Management Platform 2 3scale-amp2/system-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Hardened Images prometheus3.13 3.13.1-0.1.hum1
    not affected: vulnerable code not present
  • Red Hat Satellite 6 tfm-rubygem-graphql
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
rubygems websocket-driver
<0.8.1
0.8.1

Affected products

  • faye websocket-driver-ruby

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.