CVE-2026-26287: External Secrets Operator Remote Code Execution Vulnerability
HIGHCVE-2026-26287 is a HIGH (CVSS 7.1) remote code execution vulnerability (CWE-696: Incorrect Behavior Order) affecting External Secrets Operator libraries in the Go ecosystem. The issue involves label enforcement bypass in webhook generator enables secret exfiltration. Remediation is available by upgrading affected packages to version 1.3.2.
CVE-2026-26287 at a Glance
Security Impact
CVSS: 7.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N).
How to Fix CVE-2026-26287
To remediate this vulnerability, upgrade all affected External Secrets Operator dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/external-secrets/external-secrets to 1.3.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/external-secrets/external-secretsHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-26287, inspect your project dependencies for External Secrets Operator:
inspect dependencies for github.com/external-secrets/external-secretsAnalyze the terminal output to locate any version of External Secrets Operator in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.2), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-696: Incorrect Behavior Order, where the product performs multiple related behaviors, but the behaviors are performed in the wrong order in ways that may produce resultant weaknesses. In External Secrets Operator, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-26287 Affected External Secrets Operator Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/external-secrets/external-secrets
|
Go |
≥ 0.10.0
< 1.3.2
|
1.3.2
|
References
Frequently Asked Questions
What is CVE-2026-26287?
Which External Secrets Operator versions are affected?
What version fixes CVE-2026-26287?
Is github.com/external-secrets/external-secrets affected?
What is the CVSS score of CVE-2026-26287?
What CWE is associated with CVE-2026-26287?
How can I check Go dependencies for CVE-2026-26287?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-q7hv-xx6h-q2x8",
"modified" : "2026-10-06T15:29:25Z",
"published" : "2026-10-06T15:29:25Z",
"aliases" : [ "CVE-2026-26287" ],
"summary" : "External Secrets Operator: label enforcement bypass in webhook generator enables secret exfiltration",
"details" : "## Summary\nA 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`.\n\n## Impact\nA 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.\n\n## Mitigations\nUntil you upgrade, you can reduce risk by:\n- disabling webhook generators if not needed (or denying `generators.external-secrets.io/v1alpha1` `Webhook` via an admission policy);\n- restricting RBAC: limit who can create generators of kind `Webhook`;\n- enforcing an admission policy (OPA Gatekeeper / Kyverno) requiring referenced secrets to be labeled `external-secrets.io/type=webhook`;\n- restricting egress from external-secrets controller pods to an allowlist (kubernetes `NetworkPolicy` / service mesh egress policy).\n\n## References\n- PR #5901 (fix: webhook initialization order)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/external-secrets/external-secrets"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0.10.0"
}, {
"fixed" : "1.3.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/external-secrets/external-secrets/security/advisories/GHSA-q7hv-xx6h-q2x8"
}, {
"type" : "WEB",
"url" : "https://github.com/external-secrets/external-secrets/pull/5901"
}, {
"type" : "WEB",
"url" : "https://github.com/external-secrets/external-secrets/commit/25aa09275861e3ed6fc5d2a1a60b9ac3df4a93ba"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/external-secrets/external-secrets"
}, {
"type" : "WEB",
"url" : "https://github.com/external-secrets/external-secrets/releases/tag/v1.3.2"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-696" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-10-06T15:29:25Z",
"nvd_published_at" : null
}
}