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OpenAdvisories
Medium · 4.8 CVE-2026-27854 EUVD-2026-17409GHSA-fmwh-v9r8-w9j6

Use after free when parsing EDNS options in Lua

Published Mar 31, 2026 · Updated Apr 2, 2026 · Assigned by OX

Description

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.

Affected products

VendorProductAffectedFixed
PowerDNS DNSdist 1.9.0 – < 1.9.12, 2.0.0 – < 2.0.3 1.9.12

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 dnsdist 2.0.3-1 —
Debian 13 dnsdist 1.9.14-0+deb13u1 —
Debian 12 dnsdist No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 dnsdist No fix yet —
Ubuntu 26.04 LTS dnsdist No fix yet —
Ubuntu 25.10 dnsdist No fix yet —
Ubuntu 16.04 LTS dnsdist No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 24.04 LTS dnsdist No fix yet —
Ubuntu Pro 22.04 LTS dnsdist No fix yet —
Ubuntu Pro 20.04 LTS dnsdist No fix yet —
Ubuntu Pro 18.04 LTS dnsdist No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 dnsdist 1.9.12-150700.3.9.1 SUSE-SU-2026:1618-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 dnsdist 1.9.13-160000.1.1 SUSE-SU-2026:22319-1
SLES 16.0 dnsdist 1.9.13-160000.1.1 SUSE-SU-2026:22319-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed dnsdist 2.0.3-1.1 openSUSE-SU-2026:10473-1
openSUSE Leap 16.0 dnsdist 1.9.13-160000.1.1 openSUSE-SU-2026:21015-1
ReleasePackageFixed inAdvisory
Alpine v3.24 dnsdist 2.0.4-r0 —
Alpine v3.23 dnsdist 2.0.4-r0 —

Advisories 5

References