CVE-2026-63478
isomorphic-git: Path traversal via a ".." tree-entry name writes files outside the working directory on clone/checkout
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| isomorphic-git isomorphic-git |
< 1.38.6 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-cw2g-2vwq-88w6CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/isomorphic-git/isomorphic-git/pull/2370CNA: GitHub_M · x_refsource_MISC
- https://github.com/isomorphic-git/isomorphic-git/commit/823843d1cd19182df79bc907c767f5bcecb39a0bCNA: GitHub_M · x_refsource_MISC
- https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.38.6CNA: GitHub_M · x_refsource_MISC
For agents and automation
Read public disclosures for free as Markdown or JSON. Compatible browsers also expose native WebMCP tools to search disclosures, read this page, and discover API access.
Use the ontology-linked Cyber API with x402 pay per request, or a Y2 Pro or Elite API key with the intel:cyber scope.
Endpoints and access details
https://api.y2.dev/api/v2/cyber/cveshttps://api.y2.dev/api/v2/cyber/cves/{cveId}
A workspace owner or admin can create a Pro or Elite API key. Send Authorization: Bearer <Y2_API_KEY> from your trusted agent runtime.
For x402, omit Authorization and read the HTTP 402 payment challenge before signing a retry. Public browser tools do not make payments.