Exposure of Resource to Wrong Sphere in PowerDNS Recursor - CVE-2026-40012
Published: June 25, 2026
Vulnerability identifier: #VU135383
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-40012
CWE-ID: CWE-668
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 disclose sensitive information.
The vulnerability exists due to exposure of resource to wrong sphere in the packet cache when handling ECS-enabled queries. A remote attacker can send queries using a specific ECS to disclose sensitive information.
Only configurations with ECS enabled are vulnerable.
How to mitigate CVE-2026-40012
Install security update from vendor's website.