CVE-2026-39973

Home/CVE/Apktool is a tool for reverse engineering Android APK files. In versions 3.0.0 and 3.0.1, a path traversal vulnerability

CVE

Apktool is a tool for reverse engineering Android APK files. In versions 3.0.0 and 3.0.1, a path traversal vulnerability

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.

HIGH · CVSS 7.1 EPSS 6e-05

Schedule remediation

CVSS base score ≥ 7.0

Sigma rules0 YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Vulners Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2026-39973, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

View attack path from CVE-2026-39973

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