CVE-2026-39973 Details
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.
A path traversal vulnerability has been identified in Apktool versions 3.0.0 and 3.0.1. The issue arises in the file 'ResFileDecoder.java', where the removal of a path sanitization function allows maliciously crafted APKs to write arbitrary files to the filesystem during the decoding process. This vulnerability can be exploited by embedding '../' sequences in the 'resources.arsc' Type String Pool, enabling the crafted APK to escape the designated output directory and write files to sensitive locations, such as SSH configuration or startup folders, potentially leading to remote code execution.
Users can upgrade to Apktool version 3.0.2, which restores the path sanitization function to 'ResFileDecoder.java' before file write operations, effectively mitigating the vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 22, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-22 | Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| apktool apktool | >= 3.0.0, < 3.0.2 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 23, 2026 | Initial Analysis | [email protected] |
| Apr 21, 2026 | New CVE Received | [email protected] |