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Vulnerability record · CVE-2026-33594 · published 22 April 2026

CVE-2026-33594: Powerdns dnsdist allocation without limits vulnerability

Powerdns · Dnsdist

A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.

7.5 CVSS 3.1 High EPSS 0.80% · top 45.1% CWE-770 · Allocation without limits
7.5CVSS 3.1 base score
0.80%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
17 Jun 2026Last modified by NVD

Description

A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2026-33598Powerdns dnsdist out-of-bounds read vulnerabilityA cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet c…EPSS 2.8%8.8CVE-2017-7557Powerdns dnsdist improper authentication vulnerabilitydnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.EPSS 0.83%8.2CVE-2026-33602Powerdns dnsdist heap-based buffer overflow vulnerabilityA rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write…EPSS 1.2%8.2CVE-2026-24028Powerdns dnsdist vulnerabilityAn attacker might be able to trigger an out-of-bounds read by sending a crafted DNS response packet, when custom Lua code uses newDNSPacketOverlay to…EPSS 1.0%8.1CVE-2026-33599Powerdns dnsdist out-of-bounds read vulnerabilityA rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) opti…EPSS 0.80%7.5CVE-2026-33597Powerdns dnsdist vulnerabilityPRSD detection denial of serviceEPSS 0.75%7.5CVE-2026-33254Powerdns dnsdist allocation without limits vulnerabilityAn attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial o…EPSS 0.80%7.5CVE-2026-33593Powerdns dnsdist divide by zero vulnerabilityA client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.EPSS 0.82%

Source: NIST National Vulnerability Database (record CVE-2026-33594), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.