synced 13 MIN AGO
01 Record

CVE-2026-1519

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

HighPUBLISHEDCNA: isc
CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
View raw JSON

02 Description

Excessive NSEC3 iterations cause high CPU load during insecure delegation 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 ImpactpartialSuccessful exploitation gives limited 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
1.68% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 76.8% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-09-17.
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
2026-03-25 13:25Z7 MO AGO
Last updated
2026-09-17 12:04Z1 MO AGO
Reserved
2026-01-28
Assigning CNA
isc
Record state
PUBLISHED
Severity
High (CVSS 7.5)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
  • CWE-606Unchecked Input for Loop ConditionBase
  • CWE-770Allocation of Resources Without Limits or ThrottlingBase
Data version
5.2
Document digest
b7a3cb3b9915dc79514923a4ca6e2e5ce7a80d8d68bfb1b7de8ecac2fffcdb66

05 Affected products

VendorProductVersionsPlatforms
ISCBIND 99.11.0 to 9.16.50, 9.18.0 to 9.18.46, 9.20.0 to 9.20.20, 9.21.0 to 9.21.19, 9.11.3-S1 to 9.16.50-S1, 9.18.11-S1 to 9.18.46-S1, 9.20.9-S1 to 9.20.20-S1—

06 References

07 Remediation

Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.47, 9.20.21, 9.21.20, 9.18.47-S1, or 9.20.21-S1.

08 Fixed in

AlmaLinux 8

  • bind
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-chroot
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-export-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-export-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-libs-lite
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-license
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-lite-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-utils
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-sdb
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-sdb-chroot
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-utils
    Fixed in 32:9.11.36-16.el8_10.7
  • bind9.16
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-chroot
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-devel
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-dnssec-utils
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-doc
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-libs
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-license
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-utils
    Fixed in 32:9.16.23-0.22.el8_10.5
  • python3-bind
    Fixed in 32:9.11.36-16.el8_10.7
  • python3-bind9.16
    Fixed in 32:9.16.23-0.22.el8_10.5

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

AlmaLinux 9

  • bind
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-chroot
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-devel
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-dnssec-doc
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-dnssec-utils
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-doc
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-libs
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-license
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-utils
    Fixed in 32:9.16.23-34.el9_7.2
  • bind9.18
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-chroot
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-devel
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-dnssec-utils
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-doc
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-libs
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-utils
    Fixed in 32:9.18.29-5.el9_7.4
  • python3-bind
    Fixed in 32:9.16.23-34.el9_7.2

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

AlmaLinux 10

  • bind-doc
    Fixed in 32:9.18.33-10.el10_1.3
  • bind-license
    Fixed in 32:9.18.33-10.el10_1.3

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

CloudLinux 8

  • bind
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-chroot
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-export-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-export-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-libs-lite
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-license
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-lite-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-devel
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-libs
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-pkcs11-utils
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-sdb
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-sdb-chroot
    Fixed in 32:9.11.36-16.el8_10.7
  • bind-utils
    Fixed in 32:9.11.36-16.el8_10.7
  • bind9.16
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-chroot
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-devel
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-dnssec-utils
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-doc
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-libs
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-license
    Fixed in 32:9.16.23-0.22.el8_10.5
  • bind9.16-utils
    Fixed in 32:9.16.23-0.22.el8_10.5
  • python3-bind
    Fixed in 32:9.11.36-16.el8_10.7
  • python3-bind9.16
    Fixed in 32:9.16.23-0.22.el8_10.5

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

  • bind
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-chroot
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-devel
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-dnssec-doc
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-dnssec-utils
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-doc
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-libs
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-license
    Fixed in 32:9.16.23-34.el9_7.2
  • bind-utils
    Fixed in 32:9.16.23-34.el9_7.2
  • bind9.18
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-chroot
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-devel
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-dnssec-utils
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-doc
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-libs
    Fixed in 32:9.18.29-5.el9_7.4
  • bind9.18-utils
    Fixed in 32:9.18.29-5.el9_7.4
  • python3-bind
    Fixed in 32:9.16.23-34.el9_7.2

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

  • bind-doc
    Fixed in 32:9.18.33-10.el10_1.3
  • bind-license
    Fixed in 32:9.18.33-10.el10_1.3

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

  • bind9
    Fixed in 1:9.18.47-1~deb12u1

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

Debian 13

  • bind9
    Fixed in 1:9.20.21-1~deb13u1

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

Debian 14

  • bind9
    Fixed in 1:9.20.21-1

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

Ubuntu 18.04 LTS

  • isc-dhcp
    No fix yet

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

Ubuntu 20.04 LTS

  • bind9-libs
    No fix yet

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

Ubuntu 22.04 LTS

  • bind9
    Fixed in 1:9.18.39-0ubuntu0.22.04.3
  • bind9-libs
    No fix yet

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

Ubuntu 24.04 LTS

  • bind9
    Fixed in 1:9.18.39-0ubuntu0.24.04.3
  • isc-dhcp
    No fix yet

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

Ubuntu 25.10

  • bind9
    Fixed in 1:9.20.11-1ubuntu2.2
  • isc-dhcp
    No fix yet

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

Ubuntu 26.04 LTS

  • isc-dhcp
    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

  • bind9
    Fixed in 1:9.9.5.dfsg-3ubuntu0.19+esm15
    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

  • bind9
    Fixed in 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11
    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

  • bind9
    Fixed in 1:9.11.3+dfsg-1ubuntu1.19+esm6
    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

  • bind9
    Fixed in 1:9.18.30-0ubuntu0.20.04.2+esm3
    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.