Vulnerability · Published Apr 22, 2026 · Assigned by OX
CVE-2026-33254Resource exhaustion via DoQ/DoH3 connections
Medium 5.3
In plain English
A medium-severity resource allocation without limits in DNSdist from PowerDNS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.4%top 68.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | dnsdist | 2.0.4-r0 | ALPINE-CVE-2026-33254 |
| Alpine:v3.24 | dnsdist | 2.0.4-r0 | ALPINE-CVE-2026-33254 |
| Debian:12 | dnsdist | no fix listed | DEBIAN-CVE-2026-33254 |
| Debian:13 | dnsdist | 1.9.14-0+deb13u1 | DEBIAN-CVE-2026-33254 |
| Debian:14 | dnsdist | 2.0.4-1 | DEBIAN-CVE-2026-33254 |
| Ubuntu:25.10 | dnsdist | no fix listed | UBUNTU-CVE-2026-33254 |
| Ubuntu:26.04:LTS | dnsdist | no fix listed | UBUNTU-CVE-2026-33254 |
| Ubuntu:26.10 | dnsdist | no fix listed | UBUNTU-CVE-2026-33254 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L