Out-of-bounds write in dnsdist - CVE-2026-33602
Published: April 23, 2026
Vulnerability identifier: #VU126946
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33602
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: PowerDNS.COM B.V.
Affected software:
dnsdist
dnsdist
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds write in UDP response processing when processing crafted udp responses from a backend. A remote attacker can send a crafted udp response with a query id off by one relative to the maximum configured value to cause a denial of service.
Exploitation requires a rogue backend.
How to mitigate CVE-2026-33602
Install security update from vendor's website.