CVE-2026-33056 tar-rs: unpack_in can chmod arbitrary directories by following symlinks

What is CVE-2026-33056?

CVE-2026-33056 is a medium-severity path traversal vulnerability in alexcrichton tar-rs, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

tar-rs is a tar archive reading/writing library for Rust. In versions 0.4.44 and below, when unpacking a tar archive, the tar crate's unpack_dir function uses fs::metadata() to check whether a path that already exists is a directory. Because fs::metadata() follows symbolic links, a crafted tarball containing a symlink entry followed by a directory entry with the same name causes the crate to treat the symlink target as a valid existing directory — and subsequently apply chmod to it. This allows an attacker to modify the permissions of arbitrary directories outside the extraction root. This issue has been fixed in version 0.4.45.

Weakness: CWE-61

Which versions are affected by CVE-2026-33056?

3 open source packages ship an affected version, including tar. It affects 1 product.

Products include Tar Project Tar.

How do I fix CVE-2026-33056?

Upgrade tar to 0.4.45 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-33056 being exploited?

There is no known exploitation of CVE-2026-33056 in the wild and no public exploit code.

Other vulnerabilities in alexcrichton tar-rs

• CVE-2021-38511 Links in archive can create arbitrary directories High 7.5
• CVE-2018-20990 Arbitrary file overwrite in tar-rs High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2026-33056, AZL-80315, AZL-80499, AZL-80502, AZL-80511, AZL-80523 and 17 more.