CVE-2026-0398
Resource Exhaustion and Cache Poisoning in Recursor DNS
Publication date: 2026-02-09
Last updated on: 2026-04-20
Assigner: Open-Xchange
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| powerdns | recursor | From 5.1.0 (inc) to 5.1.10 (exc) |
| powerdns | recursor | From 5.2.8 (inc) to 5.2.8 (exc) |
| powerdns | recursor | From 5.3.0 (inc) to 5.3.5 (exc) |
Helpful Resources
Exploitability
| 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability involves crafted DNS zones and CNAME chains in the Recursor component. Specifically, specially crafted zones can cause increased resource usage, which may degrade performance or availability. Additionally, crafted CNAME chains can lead to cache poisoning, a type of attack where incorrect DNS information is cached, potentially redirecting users to malicious sites.
How can this vulnerability impact me? :
The vulnerability can impact you by causing increased resource consumption on DNS recursor services, potentially leading to degraded performance or denial of service. Furthermore, cache poisoning through crafted CNAME chains can redirect users to malicious destinations, posing security risks such as phishing or malware distribution.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know