Vulnerability in Alexcrichton Tar-Rs
CVE-2026-33056
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Alexcrichton Tar-Rs — versions < 0.4.45
- Tar Project
Weakness classification (CWE)
References
- github.com/alexcrichton/tar-rs/security/advisories/GHSA-j4xf-2g29-59ph (Exploit, Mitigation, Vendor Advisory)
- github.com/alexcrichton/tar-rs/commit/17b1fd84e632071cb8eef9d3709bf347bd266446 (Patch)
Frequently asked questions
- What is CVE-2026-33056?
- CVE-2026-33056 is a medium-severity vulnerability in Alexcrichton Tar-Rs, classified under UNIX Symbolic Link (Symlink) Following. CVSS score: 6.5/10. Published 2026-03-20.
- How severe is CVE-2026-33056?
- Medium severity. CVSS v3 base score is 6.5 out of 10.