← CVE Intelligence

CVE-2026-44452

h2o is vulnerable to heap overrun PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
h2o / h2oaffected < 8dc37cb

CWE

CWE-125, CWE-170

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.