{"id":"GHSA-m8mh-x359-vm8m","summary":"Apktool: Path Traversal to Arbitrary File Write","details":"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](https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3) ([PR #4041](https://github.com/iBotPeaches/Apktool/pull/4041), December 12, 2025), which removed the `BrutIO.sanitizePath()` call that previously prevented path traversal in resource file output paths.\n\nAn 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.\n\n**Fix:** Re-introduce `BrutIO.sanitizePath()` in `ResFileDecoder.java` before file write operations.","aliases":["CVE-2026-39973"],"modified":"2026-04-23T21:41:29.553559Z","published":"2026-04-23T21:24:28Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-04-23T21:24:28Z","nvd_published_at":"2026-04-21T02:16:07Z","cwe_ids":["CWE-22"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/iBotPeaches/Apktool/security/advisories/GHSA-m8mh-x359-vm8m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39973"},{"type":"WEB","url":"https://github.com/iBotPeaches/Apktool/pull/4041"},{"type":"WEB","url":"https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3"},{"type":"PACKAGE","url":"https://github.com/iBotPeaches/Apktool"},{"type":"WEB","url":"https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2"}],"affected":[{"package":{"name":"org.apktool:apktool-lib","ecosystem":"Maven","purl":"pkg:maven/org.apktool/apktool-lib"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.0.2"}]}],"versions":["3.0.0","3.0.1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-m8mh-x359-vm8m/GHSA-m8mh-x359-vm8m.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N"}]}