Vulnerability in Powerdns Dnsdist

CVE-2026-40209

An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit t…

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40209?
CVE-2026-40209 is a medium-severity vulnerability in Powerdns Dnsdist, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 5.3/10. Published 2026-06-25.
How severe is CVE-2026-40209?
Medium severity. CVSS v3 base score is 5.3 out of 10.