Vulnerability in BIND DNS Servers Affecting ISC's GSS-API Token Authentication
CVE-2026-3039

7.5HIGH

Key Information:

Vendor

Isc
Status
Bind 9
Vendor
CVE Published:
20 May 2026

Badges

👾 Exploit Exists

What is CVE-2026-3039?

BIND servers utilizing TKEY-based authentication via GSS-API tokens face a severe risk of excessive memory consumption when processing specially crafted malicious packets. This vulnerability typically impacts deployments that integrate DNS with Active Directory or utilize Kerberos-secured DNS environments, which can lead to potential service disruptions.

Affected Version(s)

BIND 9 9.0.0 <= 9.16.50

BIND 9 9.18.0 <= 9.18.48

BIND 9 9.20.0 <= 9.20.22

References

https://kb.isc.org/docs/cve-2026-3039
vendor-advisory
https://downloads.isc.org/isc/bind9/9.18.49
patch
https://downloads.isc.org/isc/bind9/9.20.23
patch

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ISC would like to thank Vitaly Simonovich for bringing this vulnerability to our attention.
.