astral-tokio-tar insufficiently validates PAX extensions during extraction

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-32766: 0.25% estimated exploitation activity in the next 30 days; percentile 16.88 (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.

Impact In versions 0.5.6 and earlier of astral-tokio-tar, malformed PAX extensions were silently skipped when parsing tar archives. This silent skipping (rather than rejection) of invalid PAX extensions could be used as a building block for a parser differential, for example by having astral-tokio-tar silently skip a malformed GNU “long link” extension so that a subsequent parser would misinterpret the extension. In practice, exploiting this behavior in astral-tokio-tar requires a secondary misbehaving tar parser, i.e. one that insufficiently validates malformed PAX extensions and interprets them rather than skipping or erroring on them. Consequently this advisory is considered low-severity within astral-tokio-tar itself, as it requires a separate vulnerability against any unrelated tar parser. Patches Versions 0.6.0 and newer of astral-tokio-tar reject invalid PAX extensions, rather than silently skipping them. Workarounds Users are advised to upgrade to version 0.6.0 or newer to…

Published by the source

17 Mar 2026, 19:49 UTC

Last modified by the source

24 Apr 2026, 20:45 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6gx3-4362-rf54

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# Patch Next advisory brief: CVE-2026-32766

Advisory: astral-tokio-tar insufficiently validates PAX extensions during extraction
IDs: CVE-2026-32766, GHSA-6gx3-4362-rf54
Record: https://patchnext.com/advisories/cve-2026-32766 (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: Medium (CVSS 6.3)
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 0.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io astral-tokio-tar: affected <= 0.5.6; fixed in 0.6.0

## 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-6gx3-4362-rf54 (GitHub-reviewed advisory GHSA-6gx3-4362-rf54 lists affected ranges: crates.io astral-tokio-tar >=0 <=0.5.6)

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