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Kgateway transformation policy template can emit files from the container

Low severity GitHub Reviewed Published Nov 4, 2025 in kgateway-dev/kgateway • Updated Nov 4, 2025

Package

gomod github.com/kgateway-dev/kgateway/v2 (Go)

Affected versions

< 2.0.5
>= 2.1.0-agw-cel-rbac, < 2.1.0

Patched versions

2.0.5
2.1.0

Description

Summary

The transformation policy template feature in Kgateway versions through 2.0.4 allows users with TrafficPolicy creation permissions to craft transformations that read and expose arbitrary files from the dataplane container filesystem.

Description

Impact

Users with permissions to create a TrafficPolicy can create a transformation that returns files from within the dataplane container. While no secrets are mounted to the container by default, users who mount custom volumes to the dataplane should be aware of potential data exposure through this vulnerability.

This could allow unauthorized access to:

  • Configuration files within the container
  • Custom mounted volumes and their contents
  • Any files accessible to the dataplane container process

Patches

Upgrade to version 2.0.5 or 2.1.0. These versions include an updated transformation filter in envoy-gloo that prevents file access through transformation templates.

Workarounds

If you are not using transformations, you can disallow TrafficPolicy creation or restrict transformation usage using a ValidatingAdmissionPolicy to prevent exploitation while preparing to upgrade.

References

Credits

Kindly reported by @rikatz

For More Information

If you have any questions or comments about this advisory, please reach out in slack https://cloud-native.slack.com/archives/C080D3PJMS4

References

@yuval-k yuval-k published to kgateway-dev/kgateway Nov 4, 2025
Published to the GitHub Advisory Database Nov 4, 2025
Reviewed Nov 4, 2025
Last updated Nov 4, 2025

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Adjacent
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS score

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-5pmx-7r6r-wfqq

Source code

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