DEBIAN-CVE-2026-44452

Source
https://security-tracker.debian.org/tracker/CVE-2026-44452
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44452.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-44452
Upstream
Published
2026-07-16T23:16:17Z
Modified
2026-09-14T17:03:13Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Debian:12 / h2o

Package

Name
h2o
Purl
pkg:deb/debian/h2o?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.2.5+dfsg2-7
2.2.5+dfsg2-8
2.2.5+dfsg2-8.1~exp1
2.2.5+dfsg2-8.1
2.2.5+dfsg2-9
2.2.5+dfsg2-10
2.2.5+dfsg2-11

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44452.json"