websocket-driver: Resource limit bypass via message compression (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 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.
AI Analysis
Technical Summary
CVE-2026-54464 affects the websocket-driver library when used with the permessage-deflate extension. The vulnerability arises because the library performs size checks on compressed message frames instead of on the decompressed message size. This allows an attacker to bypass resource limits by sending compressed messages that decompress to a size larger than the configured maximum, potentially exhausting system resources. The issue is addressed in websocket-driver version 0.8.1 by implementing validation of message length after decompression.
Potential Impact
An attacker can bypass configured message size limits by exploiting the compression mechanism, causing the server or client to process messages larger than intended. This can lead to resource exhaustion, potentially degrading service availability or causing denial of service conditions. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade websocket-driver to version 0.8.1 or later, where the vulnerability is fixed by validating message length after decompression. No workarounds are known. Since this is a library vulnerability, applying the official fix is the recommended remediation.
websocket-driver: Resource limit bypass via message compression (CVE-2026-54464)
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.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-54464 affects the websocket-driver library when used with the permessage-deflate extension. The vulnerability arises because the library performs size checks on compressed message frames instead of on the decompressed message size. This allows an attacker to bypass resource limits by sending compressed messages that decompress to a size larger than the configured maximum, potentially exhausting system resources. The issue is addressed in websocket-driver version 0.8.1 by implementing validation of message length after decompression.
Potential Impact
An attacker can bypass configured message size limits by exploiting the compression mechanism, causing the server or client to process messages larger than intended. This can lead to resource exhaustion, potentially degrading service availability or causing denial of service conditions. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade websocket-driver to version 0.8.1 or later, where the vulnerability is fixed by validating message length after decompression. No workarounds are known. Since this is a library vulnerability, applying the official fix is the recommended remediation.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-33ph-fccm-39pj
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-54464"]
- Ecosystems
- ["RubyGems"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6a58b41268715ace43d68264
Added to database: 07/16/2026, 10:36:02 UTC
Last enriched: 07/24/2026, 21:00:04 UTC
Last updated: 09/02/2026, 10:52:10 UTC
Views: 135
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