REDHAT-BUG-2556407: High severity Internet Systems Consortium BIND 9 vulnerability
Published Oct 20, 2026
·Updated
Replaying GSS-TSIG signed UDP messages can result in memory corruption in "named". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution.
Affected Software
1 affected component
Internet Systems Consortium BIND 9
Event History
Oct 20, 2026
Data Sourced
via Red Hat·07:50 PM
DescriptionSeverityAffected Software
Frequently Asked Questions
1
Which deployments are exposed to this issue?
The issue affects named when processing GSS-TSIG-signed UDP messages. Exposure requires use of GSS-TSIG over UDP.
2
What capabilities does an attacker need to attempt exploitation?
The attacker must be able to capture a previously signed UDP message and replay it while the negotiated TSIG key remains valid. They must also be able to send crafted queries to a zone they control; successful exploitation may lead to remote code execution.