CVE-2026-34984

External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Versions 2.2.0 and below contain a vulnerability in runtime/template/v2/template.go where the v2 template engine removes env and expandenv from Sprig's TxtFuncMap() but leaves the getHostByName function accessible to user-controlled templates. Since ESO executes templates within the controller process, an attacker who can create or update templated ExternalSecret resources can invoke controller-side DNS lookups using secret-derived values. This creates a DNS exfiltration primitive, allowing fetched secret material to be leaked via DNS queries without requiring direct outbound network access from the attacker's workload. The impact is a confidentiality issue, particularly in environments where untrusted or lower-trust users can author templated ExternalSecret resources and the controller has DNS resolution capability. This issue has been fixed in version 2.3.0.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/external-secrets/external-secrets/commit/6800989bdc12782ca2605d3b8bf7f2876a16551a	Patch
https://github.com/external-secrets/external-secrets/releases/tag/v2.3.0	Product Release Notes
https://github.com/external-secrets/external-secrets/security/advisories/GHSA-r2pg-r6h7-crf3	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:external-secrets:external_secrets_operator:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-04-14 03:16

Updated : 2026-06-17 10:39

NVD link : CVE-2026-34984

Mitre link : CVE-2026-34984

CVE.ORG link : CVE-2026-34984

JSON object : View

Products Affected

external-secrets

external_secrets_operator

CWE

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

NVD-CWE-noinfo

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