Vulnerability in Composefs Tar-Rs
CVE-2026-70622
tar-rs versions 0.4.11 through 0.4.46 contain a symlink escape vulnerability in the Builder::append_dir_all() function that allows attackers to read files outside the intended source root directory by planting symlinks in an attacker-controlled directory. When a privileged process archives an untrusted directory, the function follows symlinks without verifying that resolved targets remain within the source root, causing out-of-bounds files to be included in the archive as regular files and disclosed to the attacker.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (37.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.001
Affected products
- Composefs Tar-Rs — versions 0.4.11
Weakness classification (CWE)
References
- gist.github.com/thesmartshadow/e7dac0bb690ee17b9cc142154cb11726 (technical-description, exploit)
- www.vulncheck.com/advisories/tar-rs-symlink-escape-via-append-dir-all (third-party-advisory)
Frequently asked questions
- What is CVE-2026-70622?
- CVE-2026-70622 is a medium-severity vulnerability in Composefs Tar-Rs, classified under Improper Link Resolution Before File Access. CVSS score: 6.5/10. Published 2026-08-10.
- How severe is CVE-2026-70622?
- Medium severity. CVSS v3 base score is 6.5 out of 10.