CVE-2026-40012
Information about ECS zero scoped answers might leak to clients that use a specific ECS
Description
ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled;
INFO
Published Date :
June 25, 2026, 2:16 p.m.
Last Modified :
June 25, 2026, 4:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 8ce71d90-2354-404b-a86e-bec2cc4e6981 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Disable ECS feature.
- Clear the packet cache if necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40012.
| URL | Resource |
|---|---|
| https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-08.html |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40012 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40012
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40012 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40012 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added CWE CWE-524 Added SSVC {'id': 'CVE-2026-40012', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-25T14:40:29.990781Z'} -
New CVE Received by [email protected]
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/PowerDNS/pdns', 'vendor': 'PowerDNS', 'modules': ['EDNS Client Subnet processing'], 'product': 'Recursor', 'versions': [{'status': 'affected', 'version': '5.2.0', 'lessThan': '5.2.11', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.3.0', 'lessThan': '5.3.8', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.4.0', 'lessThan': '5.4.3', 'versionType': 'semver'}], 'packageName': 'pdns-recursor', 'programFiles': ['pdns_recursor.cc'], 'collectionURL': 'https://repo.powerdns.com/', 'defaultStatus': 'unaffected'}] Added Description ECS zero scoped answers are stored in the packet cache while they should not. This impacts only configurations that have ECS enabled; Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added Reference https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-08.html