CVE-2026-33258
Received Received - Intake
Cache Allocation Vulnerability in NSEC(3) Caches Causes Resource Exhaustion

Publication date: 2026-04-22

Last updated on: 2026-04-27

Assigner: Open-Xchange

Description
By publishing and querying a crafted zone an attacker can cause allocation of large entries in the negative and aggressive NSEC(3) caches.
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Meta Information
Published
2026-04-22
Last Modified
2026-04-27
Generated
2026-06-16
AI Q&A
2026-04-22
EPSS Evaluated
2026-06-15
NVD
CVE-2026-33258
EUVD
EUVD-2026-24721
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
powerdns recursor From 5.2.0 (inc) to 5.2.9 (exc)
powerdns recursor From 5.3.0 (inc) to 5.3.6 (exc)
powerdns recursor 5.4.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-770 The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
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Executive Summary

This vulnerability occurs when an attacker publishes and queries a specially crafted DNS zone, which causes the system to allocate large entries in the negative and aggressive NSEC(3) caches.

Impact Analysis

The impact of this vulnerability is a potential denial of service due to resource exhaustion, as the allocation of large cache entries can degrade system performance or cause crashes.

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