astral-tokio-tar: unpack_in can chmod arbitrary directories by following symlinks

Exploitation

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

CVSS 4.0

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact In versions 0.6.0 and earlier of astral-tokio-tar, the unpackin API could inadvertently modify the permissions of external (i.e. non-archive) directories outside of the archive. An attacker could use this to contrite a tar archive that maliciously changes directory permissions outside of its intended hierarchy. This flaw only affects directories; individual file permissions cannot be modified via it. See GHSA-j4xf-2g29-59ph for the equivalent flaw in the tar crate. Patches Versions 0.6.1 and newer of astral-tokio-tar use fs::symlinkmetdata rather than fs::metadata, avoiding the traversal. Workarounds Users are advised to upgrade to version 0.6.1 or newer to address this advisory. Users should experience no breaking changes as a result of the patch above. Resources - GHSA-j4xf-2g29-59ph for the original tar vulnerability Attribution - Reporter: Adam Harvey (@lawngnome)

Published by the source

6 May 2026, 17:26 UTC

Last modified by the source

6 May 2026, 17:26 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xx64-wwv2-hcqq

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# Patch Next advisory brief: GHSA-xx64-wwv2-hcqq

Advisory: astral-tokio-tar: `unpack_in` can chmod arbitrary directories by following symlinks
IDs: GHSA-xx64-wwv2-hcqq
Record: https://patchnext.com/advisories/ghsa-xx64-wwv2-hcqq (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: astral-tokio-tar 0.6.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io astral-tokio-tar: affected <= 0.6.0; fixed in 0.6.1

## Suggested inspection (read-only)
- crates.io astral-tokio-tar: 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 astral-tokio-tar.
- 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-xx64-wwv2-hcqq (GitHub-reviewed advisory GHSA-xx64-wwv2-hcqq lists affected ranges: crates.io astral-tokio-tar >=0 <=0.6.0)

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