CVE-2026-97206highCWE-416

CVE-2026-97206: high-severity vulnerability in NLnet Labs Unbound

DNS-over-QUIC (DoQ) path-migration can lead to use-after-free on multi-threaded deployments.

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41Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 7.5epss 0.3%
from disclosure to weapon1 day
Published on NVDOct 21
1st PoC+1d
NLnet Labs Unbound, 1.22.0 up to and including version 1.26.1, contains a DNS-over-QUIC (DoQ) lifetime bug reachable by a remote DoQ client under multi-threaded operation. A client-triggered QUIC path migration can enter stream/connection cleanup while a mesh reply still retains a pointer to the DoQ stream. Cleanup frees the DoQ stream and when the pending mesh reply later completes it dereferences a stale pointer leading to a crash.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
NLnet Labs · Unbound
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