ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-97206

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.

Published Oct 21, 2026 · catalog updated Oct 23, 2026 · NLnet Labs Unbound, 1.22.0

Last checked Nov 6, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-97206. EPSS is 0.33%. Act only if a listed version of NLnet Labs Unbound, 1.22.0 is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (NLnet Labs Unbound, 1.22.0).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.33%
Remediation
Advisory link
Affected products
Debian:12 unbound · Debian:13 unbound · Debian:14 unbound

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 unbound1.17.1-2, 1.17.1-2+deb12u1, 1.17.1-2+deb12u2
  • Debian:13 unbound0 → 1.26.2-0+deb13u1
  • Debian:14 unbound1.22.0-2, 1.23.1-1, 1.24.0-1

How to fix CVE-2026-97206

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-97206. EPSS is 0.33%. Act only if a listed version of NLnet Labs Unbound, 1.22.0 is installed.

Which versions are affected?

Compare what you have installed with 1.17.1-2, 1.17.1-2+deb12u1, 1.17.1-2+deb12u2, 0 → 1.26.2-0+deb13u1, 1.22.0-2, 1.23.1-1, 1.24.0-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 0.33%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · NIST NVD

    Detected

    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 dereference

  2. Oct 22, 2026 · NIST NVD

    Updated

    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 dereference

  3. Oct 23, 2026 · Trivy Vulnerability DB

    Fix available

    unbound fixed in 1.26.2-0+deb13u1

  4. Oct 23, 2026 · Trivy Vulnerability DB

    Fix available

    unbound fixed in 1.26.2-0+deb13u1

  5. Oct 23, 2026 · Trivy Vulnerability DB

    Updated

    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 dereference

Sources

  • CVE.orgVulnerability recordCVE-2026-97206

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-97206

    30-day exploitation probability 0.33%

    first.org
  • NIST NVDVulnerability recordCVE-2026-97206

    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

    nvd.nist.gov
  • Tenable CVE DatabaseVulnerability recordCVE-2026-97206

    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 dereference

    tenable.com
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-97206

    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

    osv.dev

References

Freshness

Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 28, 2026
  • Trivy Vulnerability DBOct 23, 2026
  • Tenable CVE DatabaseOct 23, 2026
  • NIST NVDOct 22, 2026
  • CVE.orgOct 21, 2026