CVE-2026-3039

Description

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
bind9	26.04 LTS resolute	Fixed 1:9.20.18-1ubuntu2.1
	25.10 questing	Fixed 1:9.20.11-1ubuntu2.4
	24.04 LTS noble	Fixed 1:9.18.39-0ubuntu0.24.04.5
	22.04 LTS jammy	Fixed 1:9.18.39-0ubuntu0.22.04.4
	20.04 LTS focal	Fixed 1:9.18.30-0ubuntu0.20.04.2+esm2
	18.04 LTS bionic	Fixed 1:9.11.3+dfsg-1ubuntu1.19+esm5
	16.04 LTS xenial	Fixed 1:9.10.3.dfsg.P4-8ubuntu1.19+esm10
	14.04 LTS trusty	Fixed 1:9.9.5.dfsg-3ubuntu0.19+esm14
bind9-libs	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Vulnerable
	20.04 LTS focal	Vulnerable
isc-dhcp	26.04 LTS resolute	Not affected
	25.10 questing	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

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Notes

alexmurray

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs

mdeslaur

in focal and jammy, isc-dhcp uses the bind9-libs package This is unlikely to affect isc-dhcp's use of bind9-libs and the vendored bind9 libs, marking as negligible

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
bind9	Upstream: 83ff826 Upstream: 03ce21c

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8293-1
Bind vulnerabilities
21 May 2026

USN-8682-1
Bind vulnerabilities
26 August 2026

Cvss 3 Severity Score