RUSTSEC-2026-0068

tar-rs incorrectly ignores PAX size headers if header size is nonzero

Reported

March 19, 2026

Issued

March 23, 2026

Package

tar (crates.io)

Type

Vulnerability

Keywords

#tar

Aliases

CVSS Score

5.1 MEDIUM

CVSS Details

Attack Complexity: Low
Attack Requirements: None
Attack Vector: Network
Privileges Required: None
Availability Impact to the Subsequent System: None
Confidentiality Impact to the Subsequent System: None
Integrity Impact to the Subsequent System: None
User Interaction: Active
Availability Impact to the Vulnerable System: None
Confidentiality Impact to the Vulnerable System: Low
Integrity Impact to the Vulnerable System: Low

CVSS Vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Patched

>=0.4.45

Description

Versions 0.4.44 and below of tar-rs have conditional logic that skips the PAX size header in cases where the base header size is nonzero.

As part of CVE-2025-62518, the astral-tokio-tar project was changed to correctly honor PAX size headers in the case where it was different from the base header. This is almost the inverse of the astral-tokio-tar issue.

Any discrepancy in how tar parsers honor file size can be used to create archives that appear differently when unpacked by different archivers. In this case, the tar-rs (Rust tar) crate is an outlier in checking for the header size — other tar parsers (including e.g. Go archive/tar) unconditionally use the PAX size override. This can affect anything that uses the tar crate to parse archives and expects to have a consistent view with other parsers.

This issue has been fixed in version 0.4.45.

Advisory available under CC0-1.0 license.