Description
NLnet Labs Unbound up to and including version 1.24.1 is vulnerable to possible domain hijack attacks. Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick resolvers to update their delegation information for the zone. Usually these RRSets are used to update the resolver's knowledge of the zone's name servers. A malicious actor can exploit the possible poisonous effect by injecting NS RRSets (and possibly their respective address records) in a reply. This could be done for example by trying to spoof a packet or fragmentation attacks. Unbound would then proceed to update the NS RRSet data it already has since the new data has enough trust for it, i.e., in-zone data for the delegation point. Unbound 1.24.1 includes a fix that scrubs unsolicited NS RRSets (and their respective address records) from replies mitigating the possible poison effect. Unbound 1.24.2 includes an additional fix that scrubs unsolicited NS RRSets (and their respective address records) from YXDOMAIN and non-referral nodata replies, further mitigating the possible poison effect.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| NLnet Labs | Unbound | ≤ 1.24.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | unbound | 1.24.2-1 | — |
| Debian 13 | unbound | 1.22.0-2+deb13u1 | DSA-6071-1 |
| Debian 12 | unbound | 1.17.1-2+deb12u4 | — |
| Debian 11 | unbound | 1.13.1-1+deb11u6 | DLA-4365-2, DLA-4365-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | unbound | 1.24.2-1ubuntu1 | — |
| Ubuntu 25.10 | unbound | 1.22.0-2ubuntu2.2 | USN-7855-2, USN-7855-1 |
| Ubuntu 24.04 LTS | unbound | 1.19.2-1ubuntu3.7 | USN-7855-2, USN-7855-1 |
| Ubuntu 22.04 LTS | unbound | 1.13.1-1ubuntu5.14 | USN-7855-2, USN-7855-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | unbound | No fix yet | — |
| Ubuntu Pro 18.04 LTS | unbound | No fix yet | — |
| Ubuntu Pro 16.04 LTS | unbound | No fix yet | — |
| Ubuntu Pro 14.04 LTS | unbound | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | unbound +6 | 1.24.2-7.el10 | RHSA-2026:18556 |
| RHEL 9 | unbound +4 | 1.24.2-2.el9 | RHSA-2026:18931 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | unbound +7 | 1.24.2-11.1.hum1 | RHSA-2026:7645 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | unbound +6 | 1.24.2-7.el10 | ALSA-2026:18556 |
| AlmaLinux 9 | unbound +4 | 1.24.2-2.el9 | ALSA-2026:18931 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | unbound | 1.24.2-7.el10 | RLSA-2026:18556 |
| Rocky Linux 9 | unbound | 1.24.2-2.el9 | RLSA-2026:18931 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | unbound | 1.20.0-150600.23.13.1 | SUSE-SU-2025:4134-1 |
| SLES 15 SP6 | unbound | 1.20.0-150600.23.13.1 | SUSE-SU-2025:4134-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | unbound | 1.24.1-160000.1.1 | SUSE-SU-2026:20201-1 |
| SLES 16.0 | unbound | 1.24.1-160000.1.1 | SUSE-SU-2026:20201-1 |
| SLE Micro 6.2 | unbound | 1.24.1-160000.1.1 | SUSE-SU-2026:20180-1 |
| SLE Micro 6.1 | unbound | 1.22.0-slfo.1.1_3.1 | SUSE-SU-2025:21065-1 |
| SLE Micro 6.0 | unbound | 1.22.0-2.1 | SUSE-SU-2025:21050-1 |
| SLE Micro 5.5 | unbound | 1.20.0-150100.10.22.1 | SUSE-SU-2025:4391-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | unbound | 1.24.1-1.1 | openSUSE-SU-2025:15668-1 |
| openSUSE Leap 16.0 | unbound | 1.24.1-160000.1.1 | openSUSE-SU-2026:20139-1 |
| openSUSE Leap 15.6 | unbound | 1.20.0-150600.23.13.1 | SUSE-SU-2025:4134-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | unbound | 1.24.1-r0 | — |
| Alpine v3.23 | unbound | 1.24.1-r0 | — |
| Alpine v3.22 | unbound | 1.23.1-r1 | — |
| Alpine v3.21 | unbound | 1.22.0-r1 | — |
| Alpine v3.20 | unbound | 1.20.0-r2 | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | unbound | 1.20.0-r2 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | unbound +5 | 1.17.1-1.amzn2023.0.10 | ALAS2023-2025-1315 |
| Amazon Linux 2 | unbound +4 | 1.7.3-15.amzn2.0.12 | ALAS2-2025-3095 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | unbound | 1.19.1-5 | — |
| Azure Linux 2 (CBL-Mariner) | unbound | 1.19.1-4 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | unbound +6 | 1.24.2-7.el10 | ELSA-2026-18556 |
| Oracle Linux 9 | unbound +4 | 1.24.2-2.el9 | ELSA-2026-18931 |
Advisories 27
- ALSA-2026:18931 Moderate: unbound security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:18556 Moderate: unbound security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-0489 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Oct 21, 2026
- RHSA-2026:7645 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 6, 2026
- RHSA-2026:18931 Red Hat Security Advisory: unbound security update Red Hat Security Advisories (RHSA) · Sep 2, 2026
- RHSA-2026:18556 Red Hat Security Advisory: unbound security update Red Hat Security Advisories (RHSA) · Sep 2, 2026
- WID-SEC-2025-2386 Unbound: Schwachstelle ermöglicht Manipulation von Dateien BSI CERT-Bund (WID) · Jul 20, 2026
- ELSA-2026-18556 Moderate: unbound security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 8, 2026
- ELSA-2026-18931 Moderate: unbound security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 12, 2026
- RLSA-2026:18556 Moderate: unbound security update Rocky Linux Security Advisories · May 29, 2026
- RLSA-2026:18931 Moderate: unbound security update Rocky Linux Security Advisories · May 28, 2026
- USN-7855-2 unbound regression Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-7855-1 unbound vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2026:20139-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15668-1 libunbound8-1.24.1-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20201-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20180-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4391-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21065-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21050-1 Security update for unbound SUSE / openSUSE Security Updates · Mar 23, 2026
- WID-SEC-2026-0413 Securepoint UTM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 12, 2026
- SUSE-SU-2025:4134-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2025-1315 Moderate: unbound security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Dec 8, 2025
- ALAS2-2025-3095 Moderate: unbound security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Dec 8, 2025
- DSA-6071-1 unbound - security update Debian Security (DSA / DLA) · Dec 5, 2025
- DLA-4365-2 unbound - security update Debian Security (DSA / DLA) · Nov 30, 2025
- DLA-4365-1 unbound - security update Debian Security (DSA / DLA) · Nov 5, 2025
References
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2025-11411.txt vendor-advisory