Skip to content
OpenAdvisories
High ALSA-2025:11849 1 CVE

Important: unbound security update

Published Jul 28, 2025 · Updated Oct 29, 2026

Summary

The unbound packages provide a validating, recursive, and caching DNS or DNSSEC resolver.

Security Fix(es):

* unbound: Unbound Cache poisoning (CVE-2025-5994)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Fixed packages 5

ReleasePackageFixed in
AlmaLinux · 9 python3-unbound 1.16.2-19.el9_6.1
AlmaLinux · 9 unbound 1.16.2-19.el9_6.1
AlmaLinux · 9 unbound-devel 1.16.2-19.el9_6.1
AlmaLinux · 9 unbound-dracut 1.16.2-19.el9_6.1
AlmaLinux · 9 unbound-libs 1.16.2-19.el9_6.1

Vulnerabilities 1

  • High 8.7

    Cache poisoning via the ECS-enabled Rebirthday Attack

    A multi-vendor cache poisoning vulnerability named 'Rebirthday Attack' has been discovered in caching resolvers that support EDNS Client Subnet (ECS). Unbound is also vulnerable when compiled with ECS support, i.e., '--enable-subnet', AND configured to send E…

References

  • report
    https://access.redhat.com/security/cve/CVE-2025-5994
  • report
    https://bugzilla.redhat.com/2380949
  • advisory
    https://errata.almalinux.org/9/ALSA-2025-11849.html