Summary
External Secrets Operator: label enforcement bypass in webhook generator enables secret exfiltration
A bug in the webhook generator initialization order incorrectly cleared the label-enforcement flag (EnforceLabels) after it was set, resulting in the provider-side check for external-secrets.io/type=webhook being skipped (and the operation to succeed while it should have failed with secret does not contain needed label 'external-secrets.io/type: webhook'. Update secret label to use it with webhook.
Mitigations
Until you upgrade, you can reduce risk by:
- disabling webhook generators if not needed (or denying
generators.external-secrets.io/v1alpha1Webhookvia an admission policy); - restricting RBAC: limit who can create generators of kind
Webhook; - enforcing an admission policy (OPA Gatekeeper / Kyverno) requiring referenced secrets to be labeled
external-secrets.io/type=webhook; - restricting egress from external-secrets controller pods to an allowlist (kubernetes
NetworkPolicy/ service mesh egress policy).
References
- PR #5901 (fix: webhook initialization order)
Impact
A user with the permission to create webhook generator can set the webhook generator to a victim' secret (which was not previously labelled for webhook's use), and exfiltrate it to a malicious URL.
CVE-2026-26287 has a CVSS score of 7.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.3.2); upgrading removes the vulnerable code path.
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.
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Frequently Asked Questions
- What is CVE-2026-26287? CVE-2026-26287 is a high-severity security vulnerability in github.com/external-secrets/external-secrets (go), affecting versions >= 0.10.0, < 1.3.2. It is fixed in 1.3.2.
- How severe is CVE-2026-26287? CVE-2026-26287 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/external-secrets/external-secrets are affected by CVE-2026-26287? github.com/external-secrets/external-secrets (go) versions >= 0.10.0, < 1.3.2 is affected.
- Is there a fix for CVE-2026-26287? Yes. CVE-2026-26287 is fixed in 1.3.2. Upgrade to this version or later.
- Is CVE-2026-26287 exploitable, and should I be worried? Whether CVE-2026-26287 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-2026-26287 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-2026-26287? Upgrade
github.com/external-secrets/external-secretsto 1.3.2 or later.