Description
Unbound 1.6.4 through 1.9.4 contain a vulnerability in the ipsec module that can cause shell code execution after receiving a specially crafted answer. This issue can only be triggered if unbound was compiled with `--enable-ipsecmod` support, and ipsecmod is enabled and used in the configuration.
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 | 1.9.6-1 | — |
| Debian 13 | unbound | 1.9.6-1 | — |
| Debian 12 | unbound | 1.9.6-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | unbound +3 | 1.7.3-10.el8 | RHSA-2020:1716 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | unbound | 1.6.8-10.3.1 | SUSE-SU-2020:1772-1 |
| SLES 15 SP1 | unbound | 1.6.8-10.3.1 | SUSE-SU-2020:1772-1 |
| SLES 15 | unbound | 1.6.8-3.6.1 | SUSE-SU-2020:1819-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 | unbound | 1.6.8-3.6.1 | SUSE-SU-2020:1819-1 |
| SLE HPC 15 | unbound | 1.6.8-3.6.1 | SUSE-SU-2020:1819-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | unbound | 1.13.2-1.2 | openSUSE-SU-2024:11005-1 |
| openSUSE Leap 15.2 | unbound +1 | 1.6.8-lp152.9.3.1 | openSUSE-SU-2020:0913-1 |
| openSUSE Leap 15.1 | unbound +1 | 1.6.8-lp151.8.3.1 | openSUSE-SU-2020:0912-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | unbound | 1.9.5-r0 | — |
| Alpine v3.23 | unbound | 1.9.5-r0 | — |
| Alpine v3.22 | unbound | 1.9.5-r0 | — |
| Alpine v3.21 | unbound | 1.9.5-r0 | — |
| Alpine v3.20 | unbound | 1.9.5-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | unbound | 1.9.5-r0 | — |
| Alpine v3.18 | unbound | 1.9.5-r0 | — |
| Alpine v3.17 | unbound | 1.9.5-r0 | — |
| Alpine v3.16 | unbound | 1.9.5-r0 | — |
| Alpine v3.15 | unbound | 1.9.5-r0 | — |
| Alpine v3.14 | unbound | 1.9.5-r0 | — |
| Alpine v3.13 | unbound | 1.9.5-r0 | — |
| Alpine v3.12 | unbound | 1.9.5-r0 | — |
| Alpine v3.11 | unbound | 1.9.5-r0 | — |
| Alpine v3.10 | unbound | 1.9.1-r4 | — |
| Alpine v3.9 | unbound | 1.8.3-r3 | — |
| Alpine v3.8 | unbound | 1.7.3-r2 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | unbound +3 | 1.7.3-10.el8 | ELSA-2020-1716 |
Advisories 7
- SUSE-SU-2020:1772-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1819-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11005-1 libunbound8-1.13.2-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0913-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0912-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:1716 Red Hat Security Advisory: unbound security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- ELSA-2020-1716 Moderate: unbound security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 5, 2020
References
- [oss-security] 20191119 CVE-2019-18934 Unbound: Vulnerability in IPSEC module mailing-list
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2019-18934.txt
- https://github.com/NLnetLabs/unbound/blob/release-1.9.5/doc/Changelog
- https://www.nlnetlabs.nl/news/2019/Nov/19/unbound-1.9.5-released/
- FEDORA-2019-a29e620cd4 vendor-advisory
- openSUSE-SU-2020:0912 vendor-advisory
- openSUSE-SU-2020:0913 vendor-advisory