CVE-2026-3039 BIND 9 server memory exhaustion during GSS-API TKEY negotiation
Attackers can cause memory exhaustion and denial of service in BIND servers configured for GSS-API TKEY authentication by sending malicious packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-3039?
CVE-2026-3039 is a high-severity denial of service vulnerability in Isc Bind, published on 20 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-3039?
It affects 1 product.
Products include Isc Bind.
How do I fix CVE-2026-3039?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-3039 being exploited?
There is no known exploitation of CVE-2026-3039 in the wild and no public exploit code.
Other vulnerabilities in Isc Bind
Sources
Also known as ALPINE-CVE-2026-3039, AZL-87087, BELL-CVE-2026-3039, CLSA-2026-1780054328, CLSA-2026-1780054583, CLSA-2026-1780407449 and 6 more.