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.
History

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Ibotpeaches
Ibotpeaches apktool
Vendors & Products Ibotpeaches
Ibotpeaches apktool

Tue, 21 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 21 Apr 2026 01:45:00 +0000

Type Values Removed Values Added
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.
Title Apktool: Path Traversal to Arbitrary File Write
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-04-21T01:35:22.396Z

Updated: 2026-04-21T13:33:14.677Z

Reserved: 2026-04-08T00:01:47.627Z

Link: CVE-2026-39973

cve-icon Vulnrichment

Updated: 2026-04-21T13:33:08.739Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-21T02:16:07.903

Modified: 2026-04-21T16:20:24.180

Link: CVE-2026-39973

cve-icon Redhat

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