How severe is CVE-2026-40012?

CVE-2026-40012 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-40012 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40012?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40012 have an EU (EUVD) identifier?

Yes. CVE-2026-40012 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39356.

When was CVE-2026-40012 published?

CVE-2026-40012 was published on 2026-06-25.

CVE-2026-40012

CVE-2026-40012 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-524.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39356
Weakness: CWE-524
Published: 2026-06-25
Last modified: 2026-06-25

Description

ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled;

Frequently asked questions

What is CVE-2026-40012?: ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled;
How severe is CVE-2026-40012?: CVE-2026-40012 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-40012 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40012?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40012 have an EU (EUVD) identifier?: Yes. CVE-2026-40012 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39356.
When was CVE-2026-40012 published?: CVE-2026-40012 was published on 2026-06-25.

References

https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-08.html

Other CWE-524 vulnerabilities

CVE-2026-53943 — Critical (CVSS 9.6): Ghost is a Node.js content management system. From until 6.37.0, when Ghost is behind a shared caching layer that…
CVE-2025-64762 — Critical (CVSS 9.1): The AuthKit library for Next.js provides convenient helpers for authentication and session management using WorkOS &…
CVE-2026-50170 — High (CVSS 7.5): Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and…
CVE-2026-48901 — High (CVSS 7.5): The InputFilter::getInstance() method omitted a security sensitive parameter from the instance cache key.
CVE-2024-27917 — High (CVSS 7.5): Shopware is an open commerce platform based on Symfony Framework and Vue. The Symfony Session Handler pops the Session…
CVE-2021-24027 — High (CVSS 7.5): A cache configuration issue prior to WhatsApp for Android v2.21.4.18 and WhatsApp Business for Android v2.21.4.18 may…

Browse all CWE-524 vulnerabilities →