cvedb.io
CVE-2026-44608
MEDIUM · CVSS 5.9
EPSS exploitation probability: 0%
Published 2026-05-20T10:16:28.313 · Last modified 2026-06-17T10:51:09.273

Summary

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. Unbo

Affected products

nlnetlabs — unbound

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.