GHSA-6GX3-4362-RF54
Vulnerability from github – Published: 2026-03-17 19:49 – Updated: 2026-03-25 18:35Impact
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 address this advisory.
Most users should experience no breaking changes as a result of the patch above. Some users who attempt to extract poorly constructed tar files may experience errors; users should re-construct their tar files with a conforming tar parser.
Attribution
- Sergei Zimmerman (@xokdvium)
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.5.6"
},
"package": {
"ecosystem": "crates.io",
"name": "astral-tokio-tar"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.6.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-32766"
],
"database_specific": {
"cwe_ids": [
"CWE-436"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-17T19:49:35Z",
"nvd_published_at": "2026-03-20T00:16:18Z",
"severity": "MODERATE"
},
"details": "## Impact\n\nIn 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 \u201clong link\u201d extension so that a subsequent parser would misinterpret the extension.\n\nIn 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.\n\n## Patches\n\nVersions 0.6.0 and newer of astral-tokio-tar reject invalid PAX extensions, rather than silently skipping them. \n\n## Workarounds\n\nUsers are advised to upgrade to version 0.6.0 or newer to address this advisory.\n\nMost users should experience no breaking changes as a result of the patch above. Some users who attempt to extract poorly constructed tar files may experience errors; users should re-construct their tar files with a conforming tar parser.\n\n## Attribution\n\n- Sergei Zimmerman (@xokdvium)",
"id": "GHSA-6gx3-4362-rf54",
"modified": "2026-03-25T18:35:40Z",
"published": "2026-03-17T19:49:35Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/astral-sh/tokio-tar/security/advisories/GHSA-6gx3-4362-rf54"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32766"
},
{
"type": "WEB",
"url": "https://github.com/astral-sh/tokio-tar/commit/e5e0139cae4577eeedf5fc16b65e690bf988ce52"
},
{
"type": "PACKAGE",
"url": "https://github.com/astral-sh/tokio-tar"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0066.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "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",
"type": "CVSS_V4"
}
],
"summary": "astral-tokio-tar insufficiently validates PAX extensions during extraction"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.