CVE-2026-33599

Severity CVSS v4.0:

Pending analysis

Type:

CWE-125 Out-of-bounds Read

Publication date:

22/04/2026

Last modified:

22/04/2026

Description

A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newServer or auto_upgrade (YAML) settings. DDR upgrade is not enabled by default.

Impact

Vector 3.x

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 3.10 LOW
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector (AV): Adjacent
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

Base Score 3.x

3.10

Severity 3.x

LOW

References to Advisories, Solutions, and Tools

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