Ubuntu Security Notices USN-8139-1 USN-8139-1: cargo-c vulnerability Publication date 1 April 2026 Overview cargo-c could be made to modify permissions on arbitrary directories. Releases 25.10 Open side navigation Close side navigation Packages Details Update instructions References Related notices Packages rust-cargo-c - Helper program to build and install c-like libraries Details It was discovered that tar-rs embedded in cargo-c 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. It was discovered that tar-rs embedded in cargo-c 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 In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 25.10 questing cargo-c – 0.10.11-1ubuntu1.1 librust-cargo-c-dev – 0.10.11-1ubuntu1.1 Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-33056 CVE-2026-33056 Related notices USN-8138-1 USN-8138-1
A vulnerability (CVE-2026-33056, CVSS 6.5) in the `tar-rs` library embedded in `cargo-c` allows a symlink traversal attack when unpacking a malicious tar archive, enabling an attacker to modify permissions on arbitrary directories outside the extraction root and potentially escalate privileges. The underlying `tar` crate is affected in versions prior to 0.4.45, which is the fixed version. Ubuntu 25.10 users should update the `rust-cargo-c` package to version 0.10.11-1ubuntu1.1.