==========================================================================
Ubuntu Security Notice USN-7855-2
December 02, 2025

unbound regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.10
- Ubuntu 25.04
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

USN-7855-1 introduced a regression in Unbound

Software Description:
- 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.

Update instructions:

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

Ubuntu 25.10
  libunbound8                     1.22.0-2ubuntu2.2
  unbound                         1.22.0-2ubuntu2.2

Ubuntu 25.04
  libunbound8                     1.22.0-1ubuntu1.3
  unbound                         1.22.0-1ubuntu1.3

Ubuntu 24.04 LTS
  libunbound8                     1.19.2-1ubuntu3.7
  unbound                         1.19.2-1ubuntu3.7

Ubuntu 22.04 LTS
  libunbound8                     1.13.1-1ubuntu5.14
  unbound                         1.13.1-1ubuntu5.14

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

References:
  https://ubuntu.com/security/notices/USN-7855-2
  https://ubuntu.com/security/notices/USN-7855-1
  CVE-2025-11411, https://launchpad.net/bugs/2133715

Package Information:
  https://launchpad.net/ubuntu/+source/unbound/1.22.0-2ubuntu2.2
  https://launchpad.net/ubuntu/+source/unbound/1.22.0-1ubuntu1.3
  https://launchpad.net/ubuntu/+source/unbound/1.19.2-1ubuntu3.7
  https://launchpad.net/ubuntu/+source/unbound/1.13.1-1ubuntu5.14

Attachment: signature.asc
Description: OpenPGP digital signature

Reply via email to