CVE-2026-63478

Full vulnerability record from the local CVENow database.

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.

Severity

MEDIUM

CVSS score

5.3 (v3.1)

Vulnerability status

Deferred

Source identifier

[email protected]

Published

2026-11-03 20:18:16.240000

Last modified

2026-11-03 20:18:16.367000

View original CVE JSON

{
  "id": "CVE-2026-63478",
  "sourceIdentifier": "[email protected]",
  "published": "2026-11-03T20:18:16.240",
  "lastModified": "2026-11-03T20:18:16.367",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "isomorphic-git",
          "product": "isomorphic-git",
          "versions": [
            {
              "version": "< 1.38.6",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/isomorphic-git/isomorphic-git/commit/823843d1cd19182df79bc907c767f5bcecb39a0b",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/isomorphic-git/isomorphic-git/pull/2370",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.38.6",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-cw2g-2vwq-88w6",
      "source": "[email protected]"
    }
  ]
}