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Fencer Vulns
high 7.5

CVE-2026-97206 json

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

published 2026-10-21 19 d ago modified 2026-10-29 10 d ago also EUVD-2026-107154

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

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.

Patch / fix

  • NLnet Labs Unbound 1.26.2
  • unbound Debian 13 1.26.2-0+deb13u1
  • unbound Debian 14 1.26.2-1

debian advisories DEBIAN-CVE-2026-97206

  • unbound openSUSE Tumbleweed 1.26.2-1.1

opensuse advisories openSUSE-SU-2026:12257-1

  • unbound Azure Linux 3.0 1.26.2-1

azure linux advisories AZL-109824

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 d ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • NLnet Labs Unbound

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.