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Dnsdist EUVDEUVD-2026-17409

| CVE-2026-27854 HIGH
Use After Free (CWE-416)
2026-03-31 OX GHSA-fmwh-v9r8-w9j6
Denial Of Service Use After Free Memory Corruption Dnsdist Powerdns
7.5
CVSS 3.1 · NVD
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Severity by source

NVD PRIMARY
7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SUSE
4.8 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Primary rating from NVD.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

7
Re-analysis Queued
Jul 25, 2026 - 11:22 vuln.today
cvss_changed
Severity Changed
Jul 25, 2026 - 11:22 NVD
MEDIUM HIGH
CVSS changed
Jul 25, 2026 - 11:22 NVD
4.8 (MEDIUM) 7.5 (HIGH)
Patch released
Mar 31, 2026 - 21:13 nvd
Patch available
EUVD ID Assigned
Mar 31, 2026 - 12:15 euvd
EUVD-2026-17409
Analysis Generated
Mar 31, 2026 - 12:15 vuln.today
CVE Published
Mar 31, 2026 - 12:06 nvd
MEDIUM 4.8

DescriptionNVD

An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.

AnalysisAI

DNSdist instances using custom Lua code can be crashed via denial of service when the DNSQuestion:getEDNSOptions method accesses a modified DNS packet, triggering a use-after-free condition. This affects DNSdist across all versions and requires network access to send crafted DNS queries, but the attack demands specific Lua code patterns and high attack complexity; no public exploit or active exploitation has been confirmed, and the real-world impact is limited to environments where custom Lua DNS query handlers reference EDNS options.

Technical ContextAI

DNSdist is PowerDNS's high-performance DNS load balancer and traffic shaper, which supports custom query processing via embedded Lua scripting. The vulnerability resides in how the DNSQuestion:getEDNSOptions Lua method handles references to EDNS (Extension Mechanisms for DNS) option data within DNS packet structures. When a DNS packet is modified during processing (for example, by upstream transformations or packet rewrites), the internal pointer or reference used by getEDNSOptions may become stale, pointing to memory that has been reallocated or freed. This is a classic use-after-free condition at the memory safety level. The root cause is insufficient validation or lifetime tracking of DNS packet structures in the Lua-to-C++ boundary when EDNS options are accessed post-modification.

RemediationAI

Update DNSdist to a patched version released by PowerDNS that addresses the use-after-free condition in the DNSQuestion:getEDNSOptions method. The exact patched version number is not provided in the available data; consult the PowerDNS advisory at https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-02.html for the specific upgrade target. As an interim mitigation, review and audit custom Lua code to identify any calls to DNSQuestion:getEDNSOptions, and either remove them if unnecessary or refactor them to avoid relying on EDNS options after packet modifications. Restrict DNSdist to minimal or no custom Lua processing if feasible, reducing the attack surface. Consider network-level controls to limit DNS query sources to trusted clients.

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Same weakness CWE-416 – Use After Free

View all
CVE-2019-0708 CRITICAL POC
9.8
CVE-2015-5119 CRITICAL POC
9.8
CVE-2014-0322 HIGH POC
8.8
CVE-2012-4792 HIGH POC
8.8
CVE-2009-4324 HIGH POC
7.8
CVE-2015-0313 CRITICAL POC
9.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2013-2551 HIGH POC
8.8

Same technique Denial Of Service

View all
CVE-2015-5119 CRITICAL POC
9.8
CVE-2011-2462 CRITICAL POC
9.8
CVE-2011-0611 HIGH POC
8.8
CVE-2012-1889 HIGH POC
8.8
CVE-2012-0507 CRITICAL POC
9.8
CVE-2014-1761 HIGH POC
7.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2011-0609 HIGH POC
7.8

Vendor StatusVendor

Debian

dnsdist
Release Status Fixed Version Urgency
bullseye fixed (unfixed) end-of-life
bookworm fixed (unfixed) end-of-life
trixie vulnerable 1.9.10-1+deb13u1 -
forky vulnerable 2.0.2-1 -
sid fixed 2.0.3-1 -
(unstable) fixed 2.0.3-1 -

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

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EUVD-2026-17409 vulnerability details – vuln.today
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