CVE-2026-39973
Apktool: Path Traversal to Arbitrary File Write
- State
- Published
- Severity
- 7.1 High
- Published
- Apr 21, 2026
- Updated
- Apr 23, 2026
- Reserved
- Apr 8, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.1 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Products
| Product | Versions |
|---|---|
ApktooliBotPeaches |
|
References
- https://github.com/iBotPeaches/Apktool/security/advisories/GHSA-m8mh-x359-vm8m
- https://github.com/iBotPeaches/Apktool/pull/4041
- https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3
- https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2
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