CVE-2026-3039: BIND 9 server memory exhaustion during GSS-API TKEY negotiation

Published May 19, 2026
·
Updated

BIND 9 server memory exhaustion during GSS-API TKEY negotiation

Other sources

BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments. This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

— MITRE

Affected Software

7 affected componentsFixes available
ISC BIND 9>=9.0.0<=9.16.50, >=9.18.0<=9.18.48, >=9.20.0<=9.20.22, >=9.21.0<=9.21.21, >=9.9.3-S1<=9.16.50-S1, >=9.18.11-S1<=9.18.48-S1, >=9.20.9-S1<=9.20.22-S1
ISC BIND>=9.0.0<=9.16.50
ISC BIND>=9.18.0<9.18.49
ISC BIND>=9.20.0<9.20.23
ISC BIND>=9.21.0<9.21.22
Microsoft azl3 bind 9.20.21-1
Patch available
debian/bind9<=1:9.16.50-1~deb11u2, <=1:9.16.50-1~deb11u5, <=1:9.18.47-1~deb12u1, <=1:9.20.21-1~deb13u1
1:9.18.49-1~deb12u11:9.20.23-1~deb13u11:9.20.23-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/bind9 to a version that resolves this vulnerability.

    Fixed in 1:9.18.49-1~deb12u1Fixed in 1:9.20.23-1~deb13u1Fixed in 1:9.20.23-1
  2. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.18.49
  3. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.20.23
  4. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.21.22
  5. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.18.49-S1
  6. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.20.23-S1

Event History

May 19, 2026
Data Sourced
via Red Hat·09:49 AM
DescriptionSeverityAffected Software
May 20, 2026
CVE Published
via MITRE·01:09 PM
Data Sourced
via MITRE·01:09 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·01:16 PM
RemedyDescriptionSeverityWeaknessAffected Software
May 21, 2026
Data Sourced
via Launchpad·08:49 PM
Description
May 22, 2026
Data Sourced
via Ubuntu·08:48 PM
RemedyDescriptionSeverityAffected Software
May 23, 2026
Data Sourced
via Microsoft·08:01 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:01 AM
DescriptionSeverity
Data Sourced
via Debian·08:50 PM
DescriptionAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-3039?

CVE-2026-3039 has a high severity due to its potential for memory exhaustion in vulnerable BIND servers.

2

How do I fix CVE-2026-3039?

To fix CVE-2026-3039, upgrade your BIND server to a version that is not affected by this vulnerability.

3

Which versions of BIND 9 are affected by CVE-2026-3039?

CVE-2026-3039 affects BIND 9 versions from 9.0.0 to 9.16.50, 9.18.0 to 9.18.48, 9.20.0 to 9.20.22, and 9.21.0 to 9.21.21.

4

What are the risks associated with CVE-2026-3039?

The primary risk associated with CVE-2026-3039 is denial of service due to excessive memory consumption from processing malicious packets.

5

Is CVE-2026-3039 a remote vulnerability?

Yes, CVE-2026-3039 is a remote vulnerability that can be exploited by attackers sending specially crafted packets.

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