BIND 9 TKEY GSS-API Excessive Mem (9.16.50/9.18.48/9.20.22/9.21.21)
CVE-2026-3039 Published on May 20, 2026

BIND 9 server memory exhaustion during GSS-API TKEY negotiation
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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-3039 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Types

Missing Reference to Active Allocated Resource

The software does not properly maintain a reference to a resource that has been allocated, which prevents the resource from being reclaimed. This does not necessarily apply in languages or frameworks that automatically perform garbage collection, since the removal of all references may act as a signal that the resource is ready to be reclaimed.

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-3039

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-3039 are published in these products:

ISC BIND
 
Canonical Ubuntu Linux
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Hummingbird
 
Red Hat Openshift
 

Affected Versions

ISC BIND 9: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Hardened Images: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 9: Red Hat OpenShift Container Platform 4:

Exploit Probability

EPSS
0.56%
Percentile
42.04%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.