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

Quick assessment

Affected

isomorphic-git isomorphic-git

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

isomorphic-git 是一个专为 Node.js 和浏览器设计的纯 JavaScript 实现的 Git 工具。在 1.38.6 版本之前，其位于中的树解析器（tree parser）会接受以独立作为树条目名称的情况，因为它仅拒绝路径分隔符。当从恶意控制或遭受中间人攻击的非 GitHub 远程仓库执行克隆（clone）或检出（checkout）操作时，嵌套的条目可能突破工作树（working-tree）根目录，在任意由主机文件系统（host-backed fs）提供的父路径上写入攻击者指定的文件。这种

CVSS 5.3 · Medium Updated Nov 04, 2026

Possible ATT&CK Techniques 2 AI

T1059 · Command and Scripting Interpreter T1203 · Exploitation for Client Execution

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Vulnerability Information

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Vulnerability Title

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

Source: CVE Program / CVE List V5

Vulnerability 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.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

对路径名的限制不恰当(路径遍历)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
isomorphic-git	isomorphic-git	< 1.38.6	-

II. Public POCs for CVE-2026-63478

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-63478

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Other References for CVE-2026-63478 (4)

https://github.com/isomorphic-git/isomorphic-git/pull/2370 x_refsource_MISC
https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.38.6 x_refsource_MISC
https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-cw2g-2vwq-88w6 x_refsource_CONFIRM
https://github.com/isomorphic-git/isomorphic-git/commit/823843d1cd19182df79bc907c767f5bcecb39a0b x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-63478

Same Patch Batch · isomorphic-git · 2026-11-03 · 4 CVEs total

CVE-2026-63395	8.8 HIGH	isomorphic-git: Arbitrary file write outside the working tree via a directory symlink duri
CVE-2026-63476	4.3 MEDIUM	isomorphic-git: Unbounded memory allocation from attacker-controlled delta target size (Do
CVE-2026-63475	4.3 MEDIUM	isomorphic-git: Circular symbolic references cause non-terminating resolution (DoS)

IV. Related Vulnerabilities

Same product: isomorphic-git

Same vendor: isomorphic-git

Same weakness: CWE-22