CVE-2026-39973 is a high-severity (CVSS 7.1) Path Traversal vulnerability in org.apktool:apktool-lib. A fix is available for org.apktool:apktool-lib — see the affected versions and patch details below.
Apktool: Path Traversal to Arbitrary File Write
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-39973.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.apktool:apktool-libReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apktool:apktool-lib | ≥ 3.0.0&&< 3.0.2 | 3.0.2org.apktool:apktool-lib:3.0.2 |
Affected Products
apktoolapktoolDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apktool:apktool-lib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apktool:apktool-lib to 3.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39973 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-39973 in your dependencies?
Find it across Maven, including transitive dependencies.