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Public proof of conceptFix available

CVE-2026-39973

A public proof of concept exists; no exploitation attested.

  • Published2026-04-21
  • Fixed in3.0.2
  • WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-04-2102:16CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Versions per branch

NVD · OSV
Apktool
BranchAffectedFixed in
3.0≥ 3.0.0, < 3.0.23.0.2

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • iBotPeaches Apktool
    Affected
    • = >= 3.0.0, < 3.0.2no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-04-21

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • apktoolUbuntu:26.10all versions · no fixed version listed
  • apktoolUbuntu:26.04:LTSall versions · no fixed version listed
  • apktoolUbuntu:25.10all versions · no fixed version listed
  • apktoolUbuntu:24.04:LTSall versions · no fixed version listed
  • apktoolUbuntu:22.04:LTSall versions · no fixed version listed
  • apktoolUbuntu:20.04:LTSall versions · no fixed version listed
  • apktoolUbuntu:18.04:LTSall versions · no fixed version listed
  • apktoolUbuntu:16.04:LTSall versions · no fixed version listed

Full record on NVD

Fix

  1. Update Apktool to 3.0.2

Advisories and patches

Detection

read 2026-11-01 01:02 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Published
2026-04-21
Last Modified
2026-10-26
NVD status
Analyzed
GitHub Advisory
GHSA-m8mh-x359-vm8m

Frequently asked questions

What is CVE-2026-39973?

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.

Is CVE-2026-39973 actively exploited?

Active exploitation of CVE-2026-39973 has not been confirmed. Its EPSS score was 0.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-39973?

CVE-2026-39973 has a CVSS v3 base score of 7.1 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

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