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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| iBotPeaches | Apktool | >= 3.0.0, < 3.0.2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | apktool | No fix yet | — |
| Ubuntu 26.04 LTS | apktool | No fix yet | — |
| Ubuntu 25.10 | apktool | No fix yet | — |
| Ubuntu 24.04 LTS | apktool | No fix yet | — |
| Ubuntu 22.04 LTS | apktool | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | apktool | No fix yet | — |
| Ubuntu 18.04 LTS | apktool | No fix yet | — |
| Ubuntu 16.04 LTS | apktool | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
frawlaboy/CVE-2026-39973-PoC ★ 3 · Apr 30, 2026
Proof of concept (builder) for CVE-2026-39973 (apktool)
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.apktool:apktool-lib | >= 3.0.0, < 3.0.2 | 3.0.2 | GHSA-m8mh-x359-vm8m |
References
- https://github.com/iBotPeaches/Apktool/security/advisories/GHSA-m8mh-x359-vm8m
- https://github.com/iBotPeaches/Apktool/pull/4041
- https://github.com/iBotPeaches/Apktool/commit/e10a0450c7afcd9462c0b76bcbff0e7428b92bdd#diff-cd531ebe1014bfd18185bf21585ca5cdb16fbcb07703ebc47949a1b4e4e36bc3
- https://github.com/iBotPeaches/Apktool/releases/tag/v3.0.2