cvedb.io
CVE-2026-54340
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-07-17T00:16:25.810 · Last modified 2026-07-17T00:16:25.810

Summary

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams, and depending on the configuration, additional limits are needed to bound decoded header state and prevent attack. This issue has been fixed by commit 9265bdd.

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.