USN-7855-2: Unbound regression

Publication date

2 December 2025

Overview

USN-7855-1 introduced a regression in Unbound


Packages

  • unbound - validating, recursive, caching DNS resolver

Details

USN-7855-1 fixed vulnerabilities in Unbound. It was discovered that the fix
for CVE-2025-11411 was incomplete. This update fixes the problem.

Original advisory 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.

USN-7855-1 fixed vulnerabilities in Unbound. It was discovered that the fix
for CVE-2025-11411 was incomplete. This update fixes the problem.

Original advisory 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.

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 –  1.22.0-2ubuntu2.2
unbound –  1.22.0-2ubuntu2.2
25.04 plucky libunbound8 –  1.22.0-1ubuntu1.3
unbound –  1.22.0-1ubuntu1.3
24.04 LTS noble libunbound8 –  1.19.2-1ubuntu3.7
unbound –  1.19.2-1ubuntu3.7
22.04 LTS jammy libunbound8 –  1.13.1-1ubuntu5.14
unbound –  1.13.1-1ubuntu5.14

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