CVE-2026-44452 – h2o is vulnerable to heap overrun

CVE ID :CVE-2026-44452

Published : July 16, 2026, 11:16 p.m. | 18 minutes ago

Description :h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 8dc37cb, when h2o receives a ClientHello message over TLS or QUIC and it contains a zero-length SNI extension, the h2o server runs over the zero-length hostname while trying to copy the hostname, assuming that it is NULL-terminated. This is a potential denial-of-service attack vector in sense that it might trigger segmentation violation. This issue has been fixed by commit 8dc37cb.

Severity: 5.9 | MEDIUM

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