USN-7855-1: Unbound vulnerability

Publication date

4 November 2025

Overview

Unbound could be made to hijack domains if it received specially crafted network traffic.


Packages

  • unbound - validating, recursive, caching DNS resolver

Details

Yuxiao Wu, Yunyi Zhang, Baojun Liu, and Haixin Duan discovered that Unbound
incorrectly handled certain promiscuous NS RRSets. A remote attacker could
possibly use this issue to perform a domain hijack attack.

Yuxiao Wu, Yunyi Zhang, Baojun Liu, and Haixin Duan discovered that Unbound
incorrectly handled certain promiscuous NS RRSets. A remote attacker could
possibly use this issue to perform a domain hijack attack.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
25.10 questing libunbound8 –  1.22.0-2ubuntu2.1
unbound –  1.22.0-2ubuntu2.1
25.04 plucky libunbound8 –  1.22.0-1ubuntu1.2
unbound –  1.22.0-1ubuntu1.2
24.04 LTS noble libunbound8 –  1.19.2-1ubuntu3.6
unbound –  1.19.2-1ubuntu3.6
22.04 LTS jammy libunbound8 –  1.13.1-1ubuntu5.13
unbound –  1.13.1-1ubuntu5.13

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