Apktool: Path Traversal to Arbitrary File Write

{
  "id": "5fd81f5d67f4dc27469a5cc1f735c27595e75193e8baed9fb0283abd5eaaad82",
  "url": "https://osv.dev/vulnerability/CVE-2026-39973",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Apktool: Path Traversal to Arbitrary File Write",
    "summary": "Apktool is a tool for reverse engineering Android APK files. In versions 3.0.0 and 3.0.1, a path traversal vulnerability in `brut/androlib/res/decoder/ResFileDecoder.java` allows a maliciously crafted APK to write arbitrary files to the filesystem during standard decoding (`apktool d`). This is a security regression introduced in commit e10a045 (PR #4041, December 12, 2025), which removed the `BrutIO.sanitizePath()` call that previously prevented path traversal in resource file output paths. An attacker can embed `../` sequences in the `resources.arsc` Type String Pool to escape the output directory and write files to arbitrary locations, including `~/.ssh/config`, `~/.bashrc`, or Windows Startup folders, escalating to RCE. The fix in version 3.0.2 re-introduces `BrutIO.sanitizePath()` in `ResFileDecoder.java` before file write operations.",
    "evidence": "osv:CVE-2026-39973",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-39973",
      "aliases": [
        "CVE-2026-39973",
        "GHSA-m8mh-x359-vm8m"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ibotpeaches/apktool",
              "type": "GIT",
              "events": [
                {
                  "introduced": "f770b39e425af4fa6ac4ca1e9ea6c4824339c6d3"
                },
                {
                  "fixed": "1c1d15b070c2138d958fa8b685d430c49c4bb117"
                },
                {
                  "fixed": "e10a0450c7afcd9462c0b76bcbff0e7428b92bdd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:apktool:apktool:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "3.0.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e10a0450c7afcd9462c0b76bcbff0e7428b92bdd"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1c1d15b070c2138d958fa8b685d430c49c4bb117"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.0.2"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.0.1",
            "v3.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39973.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.229732119Z",
      "provider": "osv",
      "references": [
        "https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39973.json",
        "https://github.com/iBotPeaches/Apktool/security/advisories/GHSA-m8mh-x359-vm8m",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-39973",
        "https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3",
        "https://github.com/iBotPeaches/Apktool/pull/4041"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39973.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-39973",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504669,
  "published_at": "2026-04-21T01:35:22.396+00:00"
}