PT-2026-52381 · Powerdns · Dnsdist

Qifan Zhang · Published 2026-06-25 · Updated 2026-06-25 · CVE-2026-40209

Mitre

CVSS v3.1

5.3

Medium

Base vector

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

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 to the number of concurrent connections to this backend, or if the process runs out of file descriptors.

Fix

Related Identifiers

CVE-2026-40209

Affected Products

Dnsdist

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-40209 · Security Note
• https://dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html · Note