Allocation of Resources Without Limits or Throttling in PowerDNS Recursor - CVE-2026-33256
Published: April 22, 2026
Vulnerability identifier: #VU126845
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33256
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource allocation in internal web server when handling crafted HTTP requests. A remote attacker can send a crafted HTTP request to cause a denial of service.
Note, the internal web server is disabled by default.
Affected software
PowerDNS Recursor
How to mitigate CVE-2026-33256
Install security update from vendor's website.
PowerDNS Recursor - addressed in versions 5.3.6, 5.4.1