CVE-2026-82717
unbound: Unbound: Remote Code Execution Vulnerability in CNAME Synthesis
Severity by source
Trivy's own label is CRITICAL. Rated critical by NVD, AlmaLinux, Oracle, Rocky Linux. Rated lower by Red Hat (high), Amazon (high), Azure Linux (high), Ubuntu (medium).
Description
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in that can progressively corrupt heap memory and under certain systems and compilation options could lead to remote code execution. The vulnerability starts when CNAME synthesis during an upstream response needs to enforce(rewrite) a max TTL value in the packet buffer. Coupled with a compression pointer that points to the overwritten value and invalidates the domain name, it leads to an error path that does not properly move the buffer position and allows for the heap buffer overflow. Since this is heavily reliant on heap memory layout, results are memory corruption that eventually leads to a crash and under specific systems and compilation options remote code execution.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| alma 10 | python3-unbound, unbound, unbound-anchor and 4 more | 1.24.2-7.el10_2.6 |
| alma 8 | python3-unbound, unbound, unbound-devel and 1 more | 1.16.2-5.14.el8_10.4 |
| alma 9 | python3-unbound, unbound, unbound-devel and 2 more | 1.24.2-3.el9_8.8 |
| Oracle Linux 8 | python3-unbound, unbound, unbound-devel and 1 more | 1.16.2-5.14.el8_10.4 |
| Oracle Linux 9 | python3-unbound, unbound, unbound-devel and 2 more | 1.24.2-3.el9_8.8 |
| rocky 10 | python3-unbound, unbound, unbound-anchor and 3 more | 1.24.2-7.el10_2.6 |
| rocky 8 | python3-unbound, unbound, unbound-devel and 1 more | 1.16.2-5.14.el8_10.4 |
| rocky 9 | python3-unbound, unbound, unbound-dracut and 1 more | 1.24.2-3.el9_8.8 |
| alpine 3.22 | unbound | 1.25.2-r0 |
| alpine 3.23 | unbound | 1.25.2-r0 |
| alpine 3.24 | unbound | 1.25.2-r2 |
| alpine edge | unbound | 1.26.1-r0 |
Show all 147 entries from 45 sources
| Source | Package | Fixed in |
|---|---|---|
| alma 10 | python3-unbound | 1.24.2-7.el10_2.6 |
| alma 10 | unbound | 1.24.2-7.el10_2.6 |
| alma 10 | unbound-anchor | 1.24.2-7.el10_2.6 |
| alma 10 | unbound-devel | 1.24.2-7.el10_2.6 |
| alma 10 | unbound-dracut | 1.24.2-7.el10_2.6 |
| alma 10 | unbound-libs | 1.24.2-7.el10_2.6 |
| alma 10 | unbound-utils | 1.24.2-7.el10_2.6 |
| alma 8 | python3-unbound | 1.16.2-5.14.el8_10.4 |
| alma 8 | unbound | 1.16.2-5.14.el8_10.4 |
| alma 8 | unbound-devel | 1.16.2-5.14.el8_10.4 |
| alma 8 | unbound-libs | 1.16.2-5.14.el8_10.4 |
| alma 9 | python3-unbound | 1.24.2-3.el9_8.8 |
| alma 9 | unbound | 1.24.2-3.el9_8.8 |
| alma 9 | unbound-devel | 1.24.2-3.el9_8.8 |
| alma 9 | unbound-dracut | 1.24.2-3.el9_8.8 |
| alma 9 | unbound-libs | 1.24.2-3.el9_8.8 |
| Oracle Linux 8 | python3-unbound | 1.16.2-5.14.el8_10.4 |
| Oracle Linux 8 | unbound | 1.16.2-5.14.el8_10.4 |
| Oracle Linux 8 | unbound-devel | 1.16.2-5.14.el8_10.4 |
| Oracle Linux 8 | unbound-libs | 1.16.2-5.14.el8_10.4 |
| Oracle Linux 9 | python3-unbound | 1.24.2-3.el9_8.8 |
| Oracle Linux 9 | unbound | 1.24.2-3.el9_8.8 |
| Oracle Linux 9 | unbound-devel | 1.24.2-3.el9_8.8 |
| Oracle Linux 9 | unbound-dracut | 1.24.2-3.el9_8.8 |
| Oracle Linux 9 | unbound-libs | 1.24.2-3.el9_8.8 |
| rocky 10 | python3-unbound | 1.24.2-7.el10_2.6 |
| rocky 10 | unbound | 1.24.2-7.el10_2.6 |
| rocky 10 | unbound-anchor | 1.24.2-7.el10_2.6 |
| rocky 10 | unbound-dracut | 1.24.2-7.el10_2.6 |
| rocky 10 | unbound-libs | 1.24.2-7.el10_2.6 |
| rocky 10 | unbound-utils | 1.24.2-7.el10_2.6 |
| rocky 8 | python3-unbound | 1.16.2-5.14.el8_10.4 |
| rocky 8 | unbound | 1.16.2-5.14.el8_10.4 |
| rocky 8 | unbound-devel | 1.16.2-5.14.el8_10.4 |
| rocky 8 | unbound-libs | 1.16.2-5.14.el8_10.4 |
| rocky 9 | python3-unbound | 1.24.2-3.el9_8.8 |
| rocky 9 | unbound | 1.24.2-3.el9_8.8 |
| rocky 9 | unbound-dracut | 1.24.2-3.el9_8.8 |
| rocky 9 | unbound-libs | 1.24.2-3.el9_8.8 |
| alpine 3.22 | unbound | 1.25.2-r0 |
| alpine 3.23 | unbound | 1.25.2-r0 |
| alpine 3.24 | unbound | 1.25.2-r2 |
| alpine edge | unbound | 1.26.1-r0 |
| amazon linux 2 | python2-unbound | 1.7.3-15.amzn2.0.17 |
| amazon linux 2 | python3-unbound | 1.7.3-15.amzn2.0.17 |
| amazon linux 2 | unbound | 1.7.3-15.amzn2.0.17 |
| amazon linux 2 | unbound-debuginfo | 1.7.3-15.amzn2.0.17 |
| amazon linux 2 | unbound-devel | 1.7.3-15.amzn2.0.17 |
| amazon linux 2 | unbound-libs | 1.7.3-15.amzn2.0.17 |
| amazon linux 2023 | python3-unbound | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | python3-unbound-debuginfo | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-anchor | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-anchor-debuginfo | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-debuginfo | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-debugsource | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-devel | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-libs | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-libs-debuginfo | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-utils | 1.17.1-1.amzn2023.0.15 |
| amazon linux 2023 | unbound-utils-debuginfo | 1.17.1-1.amzn2023.0.15 |
| Azure Linux 3.0 | unbound | 0:1.26.1-1.azl3 |
| debian 11 | unbound | no fix listed |
| debian 12 | unbound | no fix listed |
| debian 13 | unbound | 1.26.1-0+deb13u1 |
| debian 14 | unbound | 1.26.1-1 |
| echo | unbound | 1.26.1 |
| rapidfort alma 10 | python3-unbound | 1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound | 0:1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound-anchor | 0:1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound-devel | 1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound-dracut | 1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound-libs | 0:1.24.2-7.el10_2.6 |
| rapidfort alma 10 | unbound-utils | 1.24.2-7.el10_2.6 |
| rapidfort alma 9 | python3-unbound | 1.24.2-3.el9_8.8 |
| rapidfort alma 9 | unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort alma 9 | unbound-dracut | 1.24.2-3.el9_8.8 |
| rapidfort alma 9 | unbound-libs | 0:1.24.2-3.el9_8.8 |
| rapidfort alpine 3.20 | unbound | 1.25.2-r0 |
| rapidfort alpine 3.21 | unbound | 1.25.2-r0 |
| rapidfort alpine 3.22 | unbound | 1.25.2-r0 |
| rapidfort alpine 3.23 | unbound | 1.25.2-r0 |
| rapidfort alpine 3.24 | unbound | 1.25.2-r2 |
| rapidfort amazon linux 2023 | python3-unbound | 1.17.1-1.amzn2023.0.15 |
| rapidfort amazon linux 2023 | unbound | 0:1.17.1-1.amzn2023.0.15 |
| rapidfort amazon linux 2023 | unbound-anchor | 0:1.17.1-1.amzn2023.0.15 |
| rapidfort amazon linux 2023 | unbound-devel | 1.17.1-1.amzn2023.0.15 |
| rapidfort amazon linux 2023 | unbound-libs | 0:1.17.1-1.amzn2023.0.15 |
| rapidfort amazon linux 2023 | unbound-utils | 1.17.1-1.amzn2023.0.15 |
| rapidfort debian 12 | rf-unbound | 0:1.26.1-0+deb13u1, 0:1.26.1-1 |
| rapidfort debian 12 | unbound | 0:1.26.1-0+deb13u1, 0:1.26.1-1 |
| rapidfort debian 13 | rf-unbound | 0:1.26.1-0+deb13u1, 0:1.26.1-1 |
| rapidfort debian 13 | unbound | 0:1.26.1-0+deb13u1, 0:1.26.1-1 |
| rapidfort fedora 41 | rf-unbound | 0:1.24.1-2.fc41 |
| rapidfort fedora 41 | rf-unbound-anchor | 0:1.24.1-2.fc41 |
| rapidfort fedora 41 | rf-unbound-libs | 0:1.24.1-2.fc41 |
| rapidfort fedora 41 | unbound | 0:1.24.1-2.fc41 |
| rapidfort fedora 41 | unbound-anchor | 0:1.24.1-2.fc41 |
| rapidfort fedora 41 | unbound-libs | 0:1.24.1-2.fc41 |
| rapidfort fedora 43 | python3-unbound | 1.26.1-1.fc43 |
| rapidfort fedora 43 | rf-unbound | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | rf-unbound-anchor | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | rf-unbound-libs | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-anchor | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-devel | 1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-dracut | 1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-libs | 0:1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-munin | 1.26.1-1.fc43 |
| rapidfort fedora 43 | unbound-utils | 1.26.1-1.fc43 |
| rapidfort Oracle Linux 10 | python3-unbound | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound-anchor | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound-devel | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound-dracut | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound-libs | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 10 | unbound-utils | 0:1.24.2-7.el10_2.6 |
| rapidfort Oracle Linux 9 | python3-unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort Oracle Linux 9 | unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort Oracle Linux 9 | unbound-devel | 0:1.24.2-3.el9_8.8 |
| rapidfort Oracle Linux 9 | unbound-dracut | 0:1.24.2-3.el9_8.8 |
| rapidfort Oracle Linux 9 | unbound-libs | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | python3-unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | rf-unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | rf-unbound-libs | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | unbound | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | unbound-dracut | 0:1.24.2-3.el9_8.8 |
| rapidfort rocky 9 | unbound-libs | 0:1.24.2-3.el9_8.8 |
| rapidfort ubuntu 20.04 | rf-unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| rapidfort ubuntu 20.04 | unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| rapidfort ubuntu 22.04 | rf-unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| rapidfort ubuntu 22.04 | unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| rapidfort ubuntu 24.04 | rf-unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| rapidfort ubuntu 24.04 | unbound | 0:1.13.1-1ubuntu5.16, 0:1.19.2-1ubuntu3.10, 0:1.24.2-1ubuntu2.3 |
| Red Hat | openshift/ose-rhel-coreos-8 | no fix listed |
| Red Hat | openshift/ose-rhel-coreos-9 | no fix listed |
| Red Hat | unbound | no fix listed |
| Red Hat | unbound-devel | no fix listed |
| Red Hat | unbound-libs | no fix listed |
| Red Hat | unbound-python | no fix listed |
| seal Red Hat 8 | seal-unbound | 1.16.2-5.8.el8_10+sp999 |
| seal Red Hat 8 | unbound | 1.16.2-5.8.el8_10+sp999 |
| ubuntu 18.04-ESM | unbound | 1.6.7-1ubuntu2.6+esm5 |
| ubuntu 20.04-ESM | unbound | 1.9.4-2ubuntu1.11+esm2 |
| ubuntu 22.04 | unbound | 1.13.1-1ubuntu5.16 |
| ubuntu 24.04 | unbound | 1.19.2-1ubuntu3.10 |
| ubuntu 26.04 | unbound | 1.24.2-1ubuntu2.3 |
References
- https://access.redhat.com/errata/RHSA-2026:71487
- https://access.redhat.com/security/cve/CVE-2026-82717
- https://bugzilla.redhat.com/2535051
- https://bugzilla.redhat.com/2535054
- https://bugzilla.redhat.com/2535059
- https://bugzilla.redhat.com/show_bug.cgi?id=2535051
- https://bugzilla.redhat.com/show_bug.cgi?id=2535054
- https://bugzilla.redhat.com/show_bug.cgi?id=2535059
All 21 references
- https://creativecommons.org/licenses/by/4.0/
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-81634
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-81642
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-82717
- https://errata.almalinux.org/9/ALSA-2026-71487.html
- https://errata.rockylinux.org/RLSA-2026:71487
- https://linux.oracle.com/cve/CVE-2026-82717.html
- https://linux.oracle.com/errata/ELSA-2026-71487.html
- https://nlnetlabs.nl/downloads/unbound/CVE-2026-82717.txt
- https://nvd.nist.gov/vuln/detail/CVE-2026-82717
- https://ubuntu.com/security/notices/USN-8873-1
- https://www.cve.org/CVERecord?id=CVE-2026-82717
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-82717.txt