Path Traversal in Isomorphic-Git
CVE-2026-63478
isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git's tree parser in src/models/GitTree.js accepts a standalone .. tree-entry name because it rejects only path separators. During clone or checkout from a malicious or man-in-the-middle-controlled non-GitHub remote, nested .. entries can escape the working-tree root and write files at attacker-selected parent paths on any host-backed fs provider. The arbitrary file write can overwrite startup or configuration files and lead to code execution. GitHub-hosted trees are not a direct source because GitHub rejects .. entries during repository integrity checks. This issue is fixed in version 1.38.6.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Isomorphic-Git — versions < 1.38.6
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-63478?
- CVE-2026-63478 is a medium-severity vulnerability in Isomorphic-Git, classified under Path Traversal. CVSS score: 5.3/10. Published 2026-11-03.
- How severe is CVE-2026-63478?
- Medium severity. CVSS v3 base score is 5.3 out of 10.