Summary
External Secrets Operator has Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore
Impact
Namespaced SecretStore resources that used CAProvider with type ConfigMap could resolve CA material from another namespace when caProvider.namespace was set.
This bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver.
The accessible data is used as CA validation material, hence it is not directly exposed.
Impact:
- Direct data exfiltration risk: low
- Existence disclosure: an attacker can infer whether a target ConfigMap/key exists in another namespace.
- Trust-boundary violation: a tenant can make its SecretStore consume CA material owned by another namespace.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-42875? CVE-2026-42875 is a medium-severity security vulnerability in github.com/external-secrets/external-secrets (go), affecting versions < 2.4.0. It is fixed in 2.4.0.
- Which versions of github.com/external-secrets/external-secrets are affected by CVE-2026-42875? github.com/external-secrets/external-secrets (go) versions < 2.4.0 is affected.
- Is there a fix for CVE-2026-42875? Yes. CVE-2026-42875 is fixed in 2.4.0. Upgrade to this version or later.
- Is CVE-2026-42875 exploitable, and should I be worried? Whether CVE-2026-42875 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-42875 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-42875? Upgrade
github.com/external-secrets/external-secretsto 2.4.0 or later.