Allocation of Resources Without Limits or Throttling in PowerDNS Recursor - CVE-2026-33258
Published: April 22, 2026
Vulnerability identifier: #VU126847
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33258
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: PowerDNS.COM B.V.
Affected software:
PowerDNS Recursor
PowerDNS Recursor
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource allocation in negative and aggressive NSEC(3) caches when processing crafted zones and DNS responses. A remote attacker can publish and query a crafted zone to cause a denial of service.
How to mitigate CVE-2026-33258
Install security update from vendor's website.