CVE-2026-42959
high
Red Hat CVSS v3 Base Score
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
0.0%
Exploitation probability in 30 days
Top 87% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Vulnerability Report
Generated by CyberWatcher
Description
A flaw was found in Unbound's DNSSEC validator when constructing chase-reply messages for validation. The code uses the wrong counter to calculate write offsets for ADDITIONAL section resource record sets. When a DNAME chain is combined with authority filtering, an uninitialized array slot is created that the validator later dereferences, causing an immediate process crash. Any application or infrastructure relying on Unbound for DNS resolution could be forced to exit unexpectedly, resulting in a denial-of-service condition.
CWE
CWE-824Affected Products
Red Hat Enterprise Linux 10Red Hat Enterprise Linux 6Red Hat Enterprise Linux 7Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9Red Hat Hardened ImagesRed Hat OpenShift Container Platform 4