CVE-2026-54464
### 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 messag…
Overview
CVE-2026-54464 is a known-severity vulnerability. It was published on July 17, 2026.
Technical description
### 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.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2026-54464?
CVE-2026-54464 is a known-severity vulnerability. It was published on July 17, 2026.
How severe is CVE-2026-54464?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2026-54464?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-54464?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-54464 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.