Vulnerability · Published Apr 22, 2026 · Assigned by OX

CVE-2026-33595DoQ/DoH3 excessive memory allocation

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

A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and DoH3 connection, as some resources were not properly released until the end of the connection.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23dnsdist2.0.4-r0ALPINE-CVE-2026-33595
Alpine:v3.24dnsdist2.0.4-r0ALPINE-CVE-2026-33595
Debian:12dnsdistno fix listedDEBIAN-CVE-2026-33595
Debian:13dnsdist1.9.14-0+deb13u1DEBIAN-CVE-2026-33595
Debian:14dnsdist2.0.4-1DEBIAN-CVE-2026-33595
Ubuntu:25.10dnsdistno fix listedUBUNTU-CVE-2026-33595
Ubuntu:26.04:LTSdnsdistno fix listedUBUNTU-CVE-2026-33595
Ubuntu:26.10dnsdistno fix listedUBUNTU-CVE-2026-33595

Affected products (as reported)

VendorProductVersions
PowerDNS DNSdist 1.9.0 – before 1.9.132.0.0 – before 2.0.4

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References