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AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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CVSS VectorNVD
Lifecycle Timeline
6DescriptionCVE.org
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.
AnalysisAI
DNSdist allows remote attackers to create unlimited concurrent DoQ (DNS over QUIC) or DoH3 (DNS over HTTPS/3) connections, triggering unbounded memory allocation and denial of service. The vulnerability affects configurations where these protocols are explicitly enabled, as both are disabled by default. No authentication is required for exploitation, and CVSS 5.3 (AC:L, AV:N) indicates straightforward network-based triggering under default conditions.
Technical ContextAI
DNSdist is an open-source DNS load balancer and traffic policy tool that supports multiple DNS transport protocols. DoQ (DNS over QUIC, RFC 9250) and DoH3 (DNS over HTTPS/3) are modern encrypted DNS transports built on UDP and QUIC/HTTP/3 respectively. When these protocols are enabled in DNSdist, the application lacks connection pooling or memory limits for concurrent sessions, allowing an attacker to exhaust server memory by opening many simultaneous connections without sending or completing DNS queries. The root cause is improper resource management during connection establishment in the affected protocol handlers, classified under improper resource validation rather than a specific CWE but conceptually related to CWE-770 (Allocation of Resources Without Limits or Throttling).
RemediationAI
Upgrade DNSdist to the patched version specified in the PowerDNS advisory at https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html. If patching cannot be immediately applied, immediately disable DoQ and DoH3 in the DNSdist configuration (e.g., comment out or remove 'addDOQLocal' and 'addDOH3Local' directives and restart the service) - this eliminates the attack surface entirely since both protocols are non-essential for standard DNS service. If DoQ/DoH3 functionality is required, implement rate limiting at the network layer (use firewall or load balancer rules to limit new connection rates from any single source) and configure OS-level socket limits (ulimit -n) and DNSdist resource quotas if available; note that rate limiting is a temporary mitigation and does not address the underlying memory leak, only slows exploitation.
dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.
Out-of-bounds read in PowerDNS dnsdist allows unauthenticated remote attackers to trigger denial of service or potential
Remote denial of service in dnsdist allows unauthenticated attackers to crash the DNS load balancer by sending specially
DNSdist fails to validate packet size bounds when rewriting DNS questions or responses via Lua methods (DNSQuestion:chan
Memory exhaustion in DNSdist allows remote, unauthenticated attackers to trigger denial of service by crafting malicious
DNSdist instances using custom Lua code can be crashed via denial of service when the DNSQuestion:getEDNSOptions method
DNSdist is vulnerable to denial of service via out-of-bounds write when processing crafted UDP responses from a rogue ba
PowerDNS dnsdist allows unauthenticated DNS over HTTPS (DoH) queries to bypass access control lists when the early_acl_d
An issue has been found in PowerDNS DNSDist before 1.3.3 allowing a remote attacker to craft a DNS query with trailing d
Denial of service in PowerDNS Authoritative, Recursor, and dnsdist via unbounded memory allocation in their internal web
Unlimited memory allocation in PowerDNS internal web server allows remote denial of service via crafted web requests. Th
dnsdist allows remote denial-of-service attacks through memory exhaustion by generating numerous error responses on sing
Same technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Fixed |
| openSUSE Leap 15.6 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP5 | Fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| SUSE Manager Proxy 4.3 | Fixed |
| SUSE Manager Proxy LTS 4.3 | Fixed |
| SUSE Manager Retail Branch Server 4.3 | Fixed |
| SUSE Manager Retail Branch Server LTS 4.3 | Fixed |
| SUSE Manager Server 4.3 | Fixed |
| SUSE Manager Server LTS 4.3 | Fixed |
| SUSE CaaS Platform 4.0 | Fixed |
| SUSE Enterprise Storage 7.1 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP5 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP6 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Fixed |
| openSUSE Leap 15.4 | Fixed |
| openSUSE Leap 15.5 | Fixed |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-24927
GHSA-wgv5-fpv8-m4jc