Kyverno apiCall automatically forwards ServiceAccount token to external endpoints (credential leak)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Kyverno's apiCall service mode automatically attaches the admission controller's ServiceAccount (SA) token to outbound HTTP requests. This results in unintended credential exposure when requests are sent to external or attacker-controlled endpoints. The behavior is insecure-by-default and not documented, enabling token exfiltration without requiring policy authors to explicitly opt in. --- Details Kyverno's apiCall executor (pkg/engine/apicall/executor.go) reads the ServiceAccount token from: /var/run/secrets/kubernetes.io/serviceaccount/token and injects it into every HTTP request as: This occurs when no explicit Authorization header is defined in the policy. Root cause This logic introduces several issues: - Implicit credential forwarding to arbitrary endpoints - No trust boundary validation (external/internal distinction) - Undocumented behavior - Header.Add instead of Set allows duplication - No token sanitization (potential trailing newline) --- PoC Preconditions -…

Published by the source

16 Apr 2026, 21:37 UTC

Last modified by the source

16 Apr 2026, 21:37 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8wfp-579w-6r25

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# Patch Next advisory brief: GHSA-8wfp-579w-6r25

Advisory: Kyverno apiCall automatically forwards ServiceAccount token to external endpoints (credential leak)
IDs: GHSA-8wfp-579w-6r25
Record: https://patchnext.com/advisories/ghsa-8wfp-579w-6r25 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/kyverno/kyverno 1.17.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/kyverno/kyverno: affected < 1.17.0; fixed in 1.17.0

## Suggested inspection (read-only)
- Go github.com/kyverno/kyverno: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/kyverno/kyverno.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8wfp-579w-6r25 (GitHub-reviewed advisory GHSA-8wfp-579w-6r25 lists affected ranges: Go github.com/kyverno/kyverno >=0 <1.17.0)

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