Description
Unbound before 1.9.5 allows an integer overflow in the regional allocator via regional_alloc. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited
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 | — |
| Debian 9 | unbound1.9 | 1.9.0-2+deb10u2~deb9u2 | DLA-2652-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | unbound | 1.9.4-2ubuntu1.2 | USN-4938-1 |
| Ubuntu 18.04 LTS | unbound | 1.6.7-1ubuntu2.4 | USN-4938-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | unbound +3 | 1.7.3-15.el8 | RHSA-2021:1853 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | unbound +3 | 1.7.3-12.el8_2 | RHSA-2022:0632 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | unbound | 1.7.3-15.el8 | RLSA-2021:1853 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLES 15 SP2 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLES 15 SP1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLES 15 | unbound | 1.6.8-3.9.1 | SUSE-SU-2022:0301-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP2 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLES for SAP 15 SP1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLES for SAP 15 | unbound | 1.6.8-3.9.1 | SUSE-SU-2022:0301-1 |
| SLE Real Time 15 SP2 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-2 |
| SLE HPC 15 SP2 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLE HPC 15 SP1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SLE HPC 15 | unbound | 1.6.8-3.9.1 | SUSE-SU-2022:0301-1 |
| SUSE Manager Server 4.1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SUSE Manager Retail Branch Server 4.1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SUSE Manager Proxy 4.1 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SUSE Enterprise Storage 7 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
| SUSE Enterprise Storage 6 | unbound | 1.6.8-10.6.1 | SUSE-SU-2022:0176-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.3 | unbound | 1.6.8-10.6.1 | openSUSE-SU-2022:0176-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | unbound +4 | 1.7.3-15.amzn2.0.1 | ALAS2-2021-1683 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | unbound +3 | 1.7.3-15.el8 | ELSA-2021-1853 |
Advisories 11
- RHSA-2022:0632 Red Hat Security Advisory: unbound security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:1853 Red Hat Security Advisory: unbound security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- USN-4938-1 unbound vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2652-1 unbound1.9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:1853 Moderate: unbound security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2022:0301-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0176-1 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0176-2 Security update for unbound SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2022:0176-1 Security update for unbound SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2021-1683 Moderate: unbound security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 19, 2024
- ELSA-2021-1853 Moderate: unbound security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 25, 2021