{"id":"CVE-2026-39973","aliases":["GHSA-m8mh-x359-vm8m"],"url":"https://o3.security/vulnerability/CVE-2026-39973","summary":"Apktool: Path Traversal to Arbitrary File Write","details":"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.","published":"2026-04-21T01:35:22.396Z","modified":"2026-08-12T03:51:14.966100213Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N"},"epss":{"score":0.00182,"percentile":0.07884,"asOf":"2026-09-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.apktool:apktool-lib","fixedVersion":"3.0.2"}],"fix":{"url":"https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3","label":"iBotPeaches/Apktool@e10a045"},"references":[{"type":"WEB","url":"https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39973.json"},{"type":"ADVISORY","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":"FIX","url":"https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3"},{"type":"FIX","url":"https://github.com/iBotPeaches/Apktool/pull/4041"},{"type":"PACKAGE","url":"https://github.com/iBotPeaches/Apktool"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:14.966100213Z"}}