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01 Record

CVE-2026-81642

Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY

CriticalPUBLISHEDCNA: NLnet Labs
CNA base score9.1 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/U:Red
View raw JSON

02 Description

Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.96% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 61.0% of scored records. A rank, not a probability.
NVD base score
9.1 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Red
NVD analysis status
Analyzed. NVD last modified this record on 2026-09-22.
Red Hat severity
Critical. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-09-16 08:30Z1 MO AGO
Last updated
2026-09-16 14:32Z1 MO AGO
Reserved
2026-09-07
Assigning CNA
NLnet Labs
Record state
PUBLISHED
Severity
Critical (CVSS 9.1)
CNA CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/U:Red
Weaknesses
  • CWE-122Heap-based Buffer OverflowVariant
Data version
5.2
Document digest
46e5ac22f4f1852bbdd0ad13b97cbe7caed4fb56e49633c0c6b91abfba73c318

05 Affected products

VendorProductVersionsPlatforms
NLnet LabsUnbound0 to < 1.26.1—

06 References

07 Remediation

This issue is fixed starting with version 1.26.1

08 Fixed in

AlmaLinux 8

  • python3-unbound
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound-devel
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound-libs
    Fixed in 1.16.2-5.14.el8_10.4

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • python3-unbound
    Fixed in 1.24.2-3.el9_8.8
  • unbound
    Fixed in 1.24.2-3.el9_8.8
  • unbound-devel
    Fixed in 1.24.2-3.el9_8.8
  • unbound-dracut
    Fixed in 1.24.2-3.el9_8.8
  • unbound-libs
    Fixed in 1.24.2-3.el9_8.8

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • python3-unbound
    Fixed in 1.24.2-7.el10_2.6
  • unbound
    Fixed in 1.24.2-7.el10_2.6
  • unbound-anchor
    Fixed in 1.24.2-7.el10_2.6
  • unbound-devel
    Fixed in 1.24.2-7.el10_2.6
  • unbound-dracut
    Fixed in 1.24.2-7.el10_2.6
  • unbound-libs
    Fixed in 1.24.2-7.el10_2.6
  • unbound-utils
    Fixed in 1.24.2-7.el10_2.6

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • python3-unbound
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound-devel
    Fixed in 1.16.2-5.14.el8_10.4
  • unbound-libs
    Fixed in 1.16.2-5.14.el8_10.4

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • python3-unbound
    Fixed in 1.24.2-3.el9_8.8
  • unbound
    Fixed in 1.24.2-3.el9_8.8
  • unbound-devel
    Fixed in 1.24.2-3.el9_8.8
  • unbound-dracut
    Fixed in 1.24.2-3.el9_8.8
  • unbound-libs
    Fixed in 1.24.2-3.el9_8.8

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • python3-unbound
    Fixed in 1.24.2-7.el10_2.6
  • unbound
    Fixed in 1.24.2-7.el10_2.6
  • unbound-anchor
    Fixed in 1.24.2-7.el10_2.6
  • unbound-devel
    Fixed in 1.24.2-7.el10_2.6
  • unbound-dracut
    Fixed in 1.24.2-7.el10_2.6
  • unbound-libs
    Fixed in 1.24.2-7.el10_2.6
  • unbound-utils
    Fixed in 1.24.2-7.el10_2.6

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • unbound
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • unbound
    Fixed in 1.26.1-0+deb13u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • unbound
    Fixed in 1.26.1-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • unbound
    Fixed in 1.13.1-1ubuntu5.16

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • unbound
    Fixed in 1.19.2-1ubuntu3.10

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • unbound
    Fixed in 1.24.2-1ubuntu2.3

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.10

  • unbound
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • unbound
    Fixed in 1.4.22-1ubuntu4.14.04.3+esm4
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • unbound
    Fixed in 1.5.8-1ubuntu1.1+esm4
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • unbound
    Fixed in 1.6.7-1ubuntu2.6+esm5
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • unbound
    Fixed in 1.9.4-2ubuntu1.11+esm2
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.