CVE-2026-40211

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.

CVSS Vector

References

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