async-tar is a tar archive reading/writing library for async Rust. Prior to version 0.6.1, async-tar mis-applies a buffered PAX size extension to an intermediary extension header (a GNU longname L, a GNU longlink K, or a PAX x/g header) instead of to the next file entry. POSIX requires a PAX extended-header record set to describe the next file entry, never an intervening extension header. Because poll_next_raw (src/archive.rs) threads the buffered PAX records into the size computation of whatever raw header it reads next — and that header can be an intermediary L — the stream cursor is advanced by an attacker-chosen amount when the L body is consumed. The parser then desyncs relative to a POSIX-correct tar parser (e.g. GNU tar), reading subsequent bytes at the wrong block boundary. This issue has been patched in version 0.6.1.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-35rm-7j9c-2f7m async-tar PAX extension-header desync enables tar entry/content smuggling
Fixes

Solution

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Workaround

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History

Wed, 02 Sep 2026 11:00:00 +0000

Type Values Removed Values Added
Description async-tar is a tar archive reading/writing library for async Rust. Prior to version 0.6.1, async-tar mis-applies a buffered PAX size extension to an intermediary extension header (a GNU longname L, a GNU longlink K, or a PAX x/g header) instead of to the next file entry. POSIX requires a PAX extended-header record set to describe the next file entry, never an intervening extension header. Because poll_next_raw (src/archive.rs) threads the buffered PAX records into the size computation of whatever raw header it reads next — and that header can be an intermediary L — the stream cursor is advanced by an attacker-chosen amount when the L body is consumed. The parser then desyncs relative to a POSIX-correct tar parser (e.g. GNU tar), reading subsequent bytes at the wrong block boundary. This issue has been patched in version 0.6.1.
Title async-tar PAX extension-header desync enables tar entry/content smuggling
Weaknesses CWE-20
CWE-843
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-02T18:57:48.269Z

Reserved: 2026-06-09T19:39:52.404Z

Link: CVE-2026-53600

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-02T16:17:17.983

Modified: 2026-09-02T19:17:21.223

Link: CVE-2026-53600

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses