CVE-2026-54490

mediumcovered by 2 sourcesfirst seen 2026-07-15

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 0.7.5, 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.

⚡ Watch CVE-2026-54490

Get an email if CVE-2026-54490 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.

Exploitation outlook

Low exploitation risk0.26% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 18% of all EPSS-scored CVEs.

Advisory coverage (2)

unknownCVE-2026-54490: websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.7.5, if this l…nvd · 2026-07-17
mediumGHSA-mp7j-qc5w-4988: websocket-driver: Resource limit bypass via message compressionghsa · 2026-07-15

External references

NVD record for CVE-2026-54490

CVE.org record

Embed the live status

— this badge updates automatically when the KEV or exploit status changes. How to embed it →

[![CVE-2026-54490 status](https://www.csirts.com/badge/CVE-2026-54490)](https://www.csirts.com/cve/CVE-2026-54490)