synced 11 MIN AGO
01 Record

CVE-2026-33278

Possible arbitrary code execution during DNSSEC validation

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

Possible arbitrary code execution during DNSSEC validation

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
1.42% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 72.6% 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
Modified. NVD last modified this record on 2026-08-25.
Red Hat severity
Important. 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
2026-05-20 09:18Z5 MO AGO
Last updated
2026-09-01 12:04Z1 MO AGO
Reserved
2026-05-07
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-416Use After FreeVariant
  • CWE-672Operation on a Resource after Expiration or ReleaseClass
Data version
5.2
Document digest
bb7b9bbf61dc8a1c9ace8c48140bcc3aa2d509dd6f8cd6ed676d8c8e29068e65

05 Affected products

VendorProductVersionsPlatforms
NLnet LabsUnbound1.19.1 to < 1.25.1—

06 References

07 Remediation

This issue is fixed starting with version 1.25.1

08 Fixed in

AlmaLinux 9

  • python3-unbound
    Fixed in 1.24.2-3.el9_8.1
  • unbound
    Fixed in 1.24.2-3.el9_8.1
  • unbound-devel
    Fixed in 1.24.2-3.el9_8.1
  • unbound-dracut
    Fixed in 1.24.2-3.el9_8.1
  • unbound-libs
    Fixed in 1.24.2-3.el9_8.1

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_2.1
  • unbound
    Fixed in 1.24.2-7.el10_2.1
  • unbound-anchor
    Fixed in 1.24.2-7.el10_2.1
  • unbound-devel
    Fixed in 1.24.2-7.el10_2.1
  • unbound-dracut
    Fixed in 1.24.2-7.el10_2.1
  • unbound-libs
    Fixed in 1.24.2-7.el10_2.1
  • unbound-utils
    Fixed in 1.24.2-7.el10_2.1

Source: 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_8.1
  • unbound
    Fixed in 1.24.2-3.el9_8.1
  • unbound-devel
    Fixed in 1.24.2-3.el9_8.1
  • unbound-dracut
    Fixed in 1.24.2-3.el9_8.1
  • unbound-libs
    Fixed in 1.24.2-3.el9_8.1

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_2.1
  • unbound
    Fixed in 1.24.2-7.el10_2.1
  • unbound-anchor
    Fixed in 1.24.2-7.el10_2.1
  • unbound-devel
    Fixed in 1.24.2-7.el10_2.1
  • unbound-dracut
    Fixed in 1.24.2-7.el10_2.1
  • unbound-libs
    Fixed in 1.24.2-7.el10_2.1
  • unbound-utils
    Fixed in 1.24.2-7.el10_2.1

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 1.22.0-2+deb13u3

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

Debian 14

  • unbound
    Fixed in 1.25.1-1

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

Ubuntu 24.04 LTS

  • unbound
    Fixed in 1.19.2-1ubuntu3.8

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

Ubuntu 25.10

  • unbound
    Fixed in 1.22.0-2ubuntu2.3

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 1.24.2-1ubuntu2.1

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.