Exposure of Resource to Wrong Sphere in PowerDNS Recursor - CVE-2026-40012

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU135383

Exposure of Resource to Wrong Sphere in PowerDNS Recursor - CVE-2026-40012

Published: June 25, 2026


Vulnerability identifier: #VU135383
CSH Severity: Medium
CVSS v4: 6.9 [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]
CVE-ID: CVE-2026-40012
CWE-ID: CWE-668
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

PowerDNS Recursor
Debian Linux
pdns-recursor (Debian package)

How to mitigate CVE-2026-40012

Install security update from vendor's website.

PowerDNS Recursor - addressed in versions 5.2.11, 5.3.8, 5.4.3
pdns-recursor (Debian package) - update to 5.2.11-0+deb13u1

External References

Related Security Bulletins