Denial of service via crafted DoH3 queries_CVE-2026-40211

5.3 / 10

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Description

An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.

Basic Information

ID CVE-2026-40211

Source OX

Published Jun 25, 2026 at 12:23

Modified Jun 25, 2026 at 13:45

Affected Product

Vendor PowerDNS

Product DNSdist

Version 1.9.0

Affected Versions PowerDNS DNSdist 1.9.0
PowerDNS DNSdist 2.0.0

CWE Classification

CWE-770

References

www.dnsdist.org /security-advisories/powerdns-advisory-for-dnsdist-2026-09.html

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