CVE-2026-33254 PUBLISHED

Resource exhaustion via DoQ/DoH3 connections

Assigner: OX
Reserved: 18.03.2026 Published: 22.04.2026 Updated: 22.04.2026

An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service. DOQ and DoH3 are disabled by default.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	Low

CVSS 3.1

Product Status

Vendor	PowerDNS
Product	DNSdist
Versions	Default: unaffected affected from 1.9.0 to 1.9.13 (excl.) affected from 2.0.0 to 2.0.4 (excl.)

Credits

Salvor Labs - https://salvor.fr finder

References

https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html

Problem Types

Allocation of Resources Without Limits or Throttling CWE