kaniko has tar archive path traversal in its build context extraction, allowing file writes outside destination directories

Exploitation

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

CVSS

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

EPSS

• CVE-2026-28406: 0.68% estimated exploitation activity in the next 30 days; percentile 52.28 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

kaniko unpacks build context archives using filepath.Join(dest, cleanedName) without enforcing that the final path stays within dest. A tar entry like ../outside.txt escapes the extraction root and writes files outside the destination directory. In environments with registry authentication, this can be chained with docker credential helpers to achieve code execution within the executor process. Affected versions = 1.25.4, <= 1.25.9. Fix: Merged with PR #326 — uses securejoin for path resolution in tar extraction. Acknowledgements kaniko thanks Oleh Konko from 1seal for discovering and reporting this issue.

Published by the source

1 Mar 2026, 01:28 UTC

Last modified by the source

1 Mar 2026, 01:28 UTC

Source last checked

26 Oct 2026, 15:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6rxq-q92g-4rmf

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# Patch Next advisory brief: CVE-2026-28406

Advisory: kaniko has tar archive path traversal in its build context extraction, allowing file writes outside destination directories
IDs: CVE-2026-28406, GHSA-6rxq-q92g-4rmf
Record: https://patchnext.com/advisories/cve-2026-28406 (revision 1, source checked 26 Oct 2026, 15:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/chainguard-dev/kaniko 1.25.10. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/chainguard-dev/kaniko: affected >= 1.25.4, < 1.25.10; fixed in 1.25.10

## Suggested inspection (read-only)
- Go github.com/chainguard-dev/kaniko: 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/chainguard-dev/kaniko.
- 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-6rxq-q92g-4rmf (GitHub-reviewed advisory GHSA-6rxq-q92g-4rmf lists affected ranges: Go github.com/chainguard-dev/kaniko >=1.25.4 <1.25.10)

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