
CVE catalog
CVE-2026-44608
NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a locking inconsistency vulnerability that when certain conditions are met (multi-threaded, RPZ XFR reload, RPZ zone with 'rpz-nsip'/'r
- Severity
- Medium · CVSS 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.26% · Oct 25, 2026
NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a locking inconsistency vulnerability that when certain conditions are met (multi-threaded, RPZ XFR reload, RPZ zone with 'rpz-nsip'/'rpz-nsdname' triggers) it could result in heap use-after-free and eventual crash. An adversary can exploit the vulnerability if conditions are first met on a vulnerable Unbound, i.e., multi-threaded, an RPZ zone with 'rpz-nsip'/'rpz-nsdname' triggers and an ongoing XFR for that RPZ zone. Local RPZ files do not trigger the vulnerability. If the timing is right and an XFR happens at the same time another thread needs to read that RPZ zone, the reader may not hold the lock long enough and the thread applying the XFR may free objects that the reader is about to walk causing the use-after-free. Unbound 1.25.1 contains a patch with a fix to the locking code.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | unbound | sid | 1.26.2-1 | fixed |
| Debian | unbound | forky | 1.26.2-1 | fixed |
| Debian | unbound | trixie | 1.22.0-2+deb13u3 | fixed |
| Debian | unbound | trixie-security | 1.26.2-0+deb13u1 | fixed |
| Debian | unbound | bookworm | 1.17.1-2+deb12u4 | vulnerable |
| Debian | unbound | bookworm-security | 1.17.1-2+deb12u3 | vulnerable |
| Cpe | unbound | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | libunbound-dev | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | libunbound8 | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | python3-unbound | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | unbound-anchor | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | unbound-host | Not reported | 1.19.2-1ubuntu3.8 | fixed |
| Cpe | unbound | Not reported | Not reported | vulnerable |
| Cpe | unbound | Not reported | 1.25.1 | fixed |
| Ubuntu | unbound | pro | 1.4.22-1ubuntu6 | vulnerable |
| Ubuntu | unbound | pro | 1.5.7-1ubuntu1 | vulnerable |
| Ubuntu | unbound | pro | 1.5.7-1ubuntu2 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1+esm1 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1+esm2 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1+esm3 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1+esm4 | vulnerable |
| Ubuntu | unbound | pro | 1.5.8-1ubuntu1.1+esm5 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.17.1-2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.18.0-2ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.18.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.1-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.3 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.4 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.5 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.6 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.7 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.8 | fixed |
| Ubuntu | unbound | 25.10 | 1.22.0-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 25.10 | 1.22.0-2ubuntu1 | vulnerable |
| Ubuntu | unbound | 25.10 | 1.22.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | 25.10 | 1.22.0-2ubuntu2.1 | vulnerable |
| Ubuntu | unbound | 25.10 | 1.22.0-2ubuntu2.2 | vulnerable |
| Ubuntu | unbound | 25.10 | 1.22.0-2ubuntu2.3 | fixed |
| Ubuntu | unbound | 26.04 | 1.22.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.22.0-2ubuntu4 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2.1 | fixed |
| Alpine | unbound | 3.22 | 1.25.2-r0 | fixed |
| Alpine | unbound | 3.23 | 1.25.2-r0 | fixed |
| Alpine | unbound | 3.24 | 1.25.1-r0 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | unbound | source | sid | 1.25.1-1 | not yet assigned | Not reported | [1137187] |
| Debian | unbound | source | forky | 1.25.1-1 | not yet assigned | Not reported | [1137187] |
| Debian | unbound | source | trixie | 1.22.0-2+deb13u3 | not yet assigned | Not reported | [1137187] |
| Debian | unbound | source | bookworm | (unfixed) | not yet assigned | Not reported | [1137187] |
| Cpe | unbound | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | libunbound-dev | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | libunbound8 | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | python3-unbound | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | unbound-anchor | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | unbound-host | cpe | Not reported | 1.19.2-1ubuntu3.8 | Not reported | Not reported | Not reported |
| Cpe | unbound | cpe | Not reported | 1.25.1 | Not reported | Not reported | Not reported |
| Ubuntu | unbound | deb | 24.04 | 1.19.2-1ubuntu3.8 | Not reported | UBUNTU-CVE-2026-44608 | Not reported |
| Ubuntu | unbound | deb | 25.10 | 1.22.0-2ubuntu2.3 | Not reported | UBUNTU-CVE-2026-44608 | Not reported |
| Ubuntu | unbound | deb | 26.04 | 1.24.2-1ubuntu2.1 | Not reported | UBUNTU-CVE-2026-44608 | Not reported |
| Alpine | unbound | apk | 3.22 | 1.25.2-r0 | Not reported | ALPINE-CVE-2026-44608 | Not reported |
| Alpine | unbound | apk | 3.23 | 1.25.2-r0 | Not reported | ALPINE-CVE-2026-44608 | Not reported |
| Alpine | unbound | apk | 3.24 | 1.25.1-r0 | Not reported | ALPINE-CVE-2026-44608 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libunbound8]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [libunbound-dev]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [python3-unbound]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound]Affected
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound-anchor]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound-host]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
[Debian 13 (Trixie)]
- [libunbound8]Fixed
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
- [libunbound-dev]Fixed
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
- [python3-unbound]Fixed
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
- [unbound]Fixed
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
- [unbound-anchor]Fixed
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
- [unbound-host]Fixed
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.22.0-2+deb13u3nvd · unbound · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_21874-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-44608]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-44608]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-44608]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-44608]
- [https://security-tracker.debian.org/tracker/CVE-2026-44608]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44608.json]
- [https://ubuntu.com/security/notices/USN-8282-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2455.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]