CVE-2026-44608

Name
CVE-2026-44608
Description
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.
NVD Severity
unknown
Other trackers
Mailing lists
Exploits
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
sep@nlnetlabs.nl https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-44608.txt

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:* unbound >= 1.14.0 < 1.25.1

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
unbound edge-main 1.25.1-r0 Jakub Jirutka <jakub@jirutka.cz> fixed
unbound edge-main 1.25.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.24.2-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.24.2-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.24.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.24.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.23.1-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.23.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.23.0-r2 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.23.0-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.23.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.22.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.21.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.20.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.19.2-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.19.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.16.3-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound edge-main 1.16.2-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.23-main 1.24.2-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.22-main 1.23.1-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.22-main 1.23.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.22-main 1.23.0-r2 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.22-main 1.21.1-r0 None possibly vulnerable
unbound 3.22-main 1.20.0-r0 None possibly vulnerable
unbound 3.22-main 1.19.2-r0 None possibly vulnerable
unbound 3.22-main 1.19.1-r0 None possibly vulnerable
unbound 3.22-main 1.16.3-r0 None possibly vulnerable
unbound 3.22-main 1.16.2-r0 None possibly vulnerable
unbound 3.21-main 1.22.0-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.21-main 1.22.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.21-main 1.21.1-r0 None possibly vulnerable
unbound 3.21-main 1.20.0-r0 None possibly vulnerable
unbound 3.21-main 1.19.2-r0 None possibly vulnerable
unbound 3.21-main 1.19.1-r0 None possibly vulnerable
unbound 3.21-main 1.16.3-r0 None possibly vulnerable
unbound 3.21-main 1.16.2-r0 None possibly vulnerable
unbound 3.20-main 1.20.0-r2 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.20-main 1.20.0-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.20-main 1.20.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.20-main 1.19.2-r0 None possibly vulnerable
unbound 3.20-main 1.19.1-r0 None possibly vulnerable
unbound 3.20-main 1.16.3-r0 None possibly vulnerable
unbound 3.20-main 1.16.2-r0 None possibly vulnerable
unbound 3.19-main 1.20.0-r2 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.19-main 1.20.0-r1 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.19-main 1.20.0-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.19-main 1.19.2-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.19-main 1.19.1-r0 Jakub Jirutka <jakub@jirutka.cz> possibly vulnerable
unbound 3.19-main 1.16.3-r0 None possibly vulnerable
unbound 3.19-main 1.16.2-r0 None possibly vulnerable