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OpenAdvisories
Medium · 5.0 CVE-2026-33259 EUVD-2026-24723GHSA-6c6h-9v3q-3wqm

Concurrent modification of RPZ data can lead to denial of servce

Published Apr 22, 2026 · Updated Apr 22, 2026 · Assigned by OX

Description

Having many concurrent transfers of the same RPZ can lead to inconsistent RPZ data, use after free and/or a crash of the recursor. Normally concurrent transfers of the same RPZ zone can only occur with a malfunctioning RPZ provider.

Affected products

VendorProductAffectedFixed
PowerDNS Recursor 5.4.0 – < 5.4.1, 5.3.0 – < 5.3.6, 5.2.0 – < 5.2.9 5.4.1

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 pdns-recursor 5.4.1-1 —
Debian 13 pdns-recursor 5.2.9-0+deb13u1 —
Debian 12 pdns-recursor No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 pdns-recursor No fix yet —
Ubuntu 26.04 LTS pdns-recursor No fix yet —
Ubuntu 25.10 pdns-recursor No fix yet —
Ubuntu 24.04 LTS pdns-recursor No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 22.04 LTS pdns-recursor No fix yet —
Ubuntu Pro 20.04 LTS pdns-recursor No fix yet —
Ubuntu Pro 18.04 LTS pdns-recursor No fix yet —
Ubuntu Pro 16.04 LTS pdns-recursor No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed pdns-recursor 5.4.8-1.1 openSUSE-SU-2026:12532-1
ReleasePackageFixed inAdvisory
Alpine v3.24 pdns-recursor 5.4.1-r0 —
Alpine v3.23 pdns-recursor 5.3.6-r0 —

Advisories 2

References