vulnerability / NVI-00011878 / Revision 3
External Secrets Operator: label enforcement bypass in webhook generator enables secret exfiltration
GitHub lists this reviewed advisory for github.com/external-secrets/external-secrets. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.1 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.244%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.15697. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/external-secrets/external-secrets
source listed>= 0.10.0, < 1.3.2
## Summary 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`. ## 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. ## Mitigations Until you upgrade, you can reduce risk by: - disabling webhook generators if not needed (or denying `generators.external-secrets.io/v1alpha1` `Webhook` via 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: w
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-q7hv-xx6h-q2x8 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-26287 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.