CVE-2026-63395

What it is

isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git's git.checkout writes new child paths through symlinked leading directory components without checking them. A malicious repository can first place a directory symlink and later replace the tree state with a child file beneath that path; the usual trigger is a clone followed by a later pull, while a single clone can trigger the issue when a symlink already exists or the consuming application accesses the tree. With Node fs on Linux or macOS, the operating system can resolve the write outside the working tree, permitting arbitrary host file writes and possible code execution. Node fs on Windows usually blocks the symlink plant without additional privilege, and browser or in-memory providers limit impact to their virtual filesystem and are affected only when they implement symlink creation and following. This issue is fixed in version 1.38.6.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.7% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-16 17:39 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-03 20:18 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-03 22:19 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.7% in the next 30 days (EPSS).
• Severity: 8.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-03 20:18 UTC

Last modified

2026-11-03 22:19 UTC

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-22 · Path traversal

Record status

Deferred

Attack profile CVSS 3.1 · 8.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63395.md and follow it. Check whether this project is affected by CVE-2026-63395. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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