Medium · CVSS 5.3CVE-2026-63478

isomorphic-git: Path traversal via a ".." tree-entry name writes files outside the working directory on clone/checkoutCVE-2026-63478

Answer in brief

CVE-2026-63478 records a Medium severity (CVSS 5.3) vulnerability in isomorphic-git: Path traversal via a ".." tree-entry name writes files outside the working directory on clone/checkout. The current sources do not mark it as known exploited. The current feed maps isomorphic-git/isomorphic-git (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 3, 2026Updated Nov 3, 2026Source checked Nov 3, 2026First seen by HOL Nov 3, 2026Material review Nov 3, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps isomorphic-git/isomorphic-git (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
isomorphic-git/isomorphic-gitgeneric	<1.38.6	1.38.6

Recommended response

Check inventory. Check lockfiles and deployed manifests for isomorphic-git/isomorphic-git.
Review the reported fix. Update isomorphic-git/isomorphic-git to 1.38.6 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Nov 3, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.