Helm Chart extraction output directory collapse via Chart.yaml name dot-segment

Exploitation

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

CVSS 4.0

4.8 · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-35206: 0.20% estimated exploitation activity in the next 30 days; percentile 9.74 (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.

Helm is a package manager for Charts for Kubernetes. In Helm versions <=3.20.1 and <=4.1.3, a specially crafted Chart will cause helm pull --untar [chart URL | repo/chartname] to write the Chart's contents to the immediate output directory (as defaulted to the current working directory; or as given by the --destination and --untardir flags), rather than the expected output directory suffixed by the chart's name. Impact The bug enables writing the Chart's contents (unpackaged/untar'ed) to the output directory <output dir/, instead of the expected <output dir/<chart name/, potentially overwriting the contents of the targeted directory. Note: a chart name containing POSIX dot-dot, or dot-dot and slashes (as if to refer to parent directories) do not resolve beyond the output directory as designed. Patches This issue has been resolved in Helm v3.20.2 and v4.1.3 A Chart with an unexpected name (those specified to be "." or ".."), or a Chart name which results in a non-unique directory will…

Published by the source

10 Apr 2026, 15:33 UTC

Last modified by the source

10 Apr 2026, 15:33 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hr2v-4r36-88hr

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# Patch Next advisory brief: CVE-2026-35206

Advisory: Helm Chart extraction output directory collapse via `Chart.yaml` name dot-segment
IDs: CVE-2026-35206, GHSA-hr2v-4r36-88hr
Record: https://patchnext.com/advisories/cve-2026-35206 (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: Medium (CVSS 4.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: helm.sh/helm/v3 3.20.2; helm.sh/helm/v4 4.1.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go helm.sh/helm/v3: affected <= 3.20.1; fixed in 3.20.2
- Go helm.sh/helm/v4: affected <= 4.1.3; fixed in 4.1.4

## Suggested inspection (read-only)
- Go helm.sh/helm/v3: check the installed version with your package manager.
- Go helm.sh/helm/v4: 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 helm.sh/helm/v3, helm.sh/helm/v4.
- 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-hr2v-4r36-88hr (GitHub-reviewed advisory GHSA-hr2v-4r36-88hr lists affected ranges: Go helm.sh/helm/v4 >=0 =0 <=3.20.1)

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