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Ubuntu Security Notice USN-8138-2
April 14, 2026

rust-tar vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

tar-rs could be made to modify permissions on arbitrary directories.

Software Description:
- rust-tar: A tar archive reading/writing library for Rust

Details:

USN-8138-1 fixed a vulnerability in tar-rs. This update provides the
corresponding update for Ubuntu 20.04 LTS.

Original advisory details:

 It was discovered that tar-rs incorrectly handled symlinks when unpacking
 a tar archive. If a user or automated system were tricked into processing
 a specially crafted tar archive, a remote attacker could use this issue to
 modify permissions of arbitrary directories outside the extraction root,
 and possibly escalate privileges.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS
  librust-tar-dev                 0.4.26-1ubuntu0.1
                                  Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-8138-2
  https://ubuntu.com/security/notices/USN-8138-1
  CVE-2026-33056