Apktool: Path Traversal to Arbitrary File Write
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.
Fix: Re-introduce BrutIO.sanitizePath() in ResFileDecoder.java before file write operations.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.apktool:apktool-lib | >= 3.0.0, < 3.0.2 | 3.0.2 |
References
- 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/pull/4041
- https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3
- https://github.com/iBotPeaches/Apktool
- https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N- Weakness (CWE)
CWE-22- Platform
- Java / Kotlin (Maven)
- Package
org.apktool:apktool-lib- Disclosed
- 23.04.2026
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-m8mh-x359-vm8m - CC BY 4.0
Vulnerability history: org.apktool:apktool-lib
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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