Allocation of Resources Without Limits or Throttling in dnsdist - CVE-2026-33254
Published: April 23, 2026
Vulnerability identifier: #VU126945
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33254
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: PowerDNS.COM B.V.
Affected software:
dnsdist
dnsdist
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in DoQ and DoH3 connection handling when opening a large number of connections. A remote attacker can open a large number of DoQ or DoH3 connections to cause a denial of service.
DoQ and DoH3 are disabled by default.
How to mitigate CVE-2026-33254
Install security update from vendor's website.