PoC Index

CVE-2026-39973

HIGH 7.1EPSS 0.2%

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.

CVSS v3.1
7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS v3.1
7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS v3.1
7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS
0.18% chance of exploitation in the next 30 days, 8th percentile
Published
2026-04-21
Updated
2026-04-23

Proof-of-concept exploits (1)

References

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