CVE-2026-39973: Apktool is a tool for reverse engineering Android APK files

Routine

HIGH 7.1UPGRADE

CVE-2026-39973 is a high-severity flaw (CVSS 7.1) affecting apktool. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 92%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-04-21
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: apktool

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-21 02:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

apktool apktool UPGRADE

Affected: >= 3.0.0 and < 3.0.2

Fixed in: 3.0.2

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy apktool || rpm -q apktool || apktool --version

2. UPGRADE to 3.0.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade apktool

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade apktool

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison apktool sudo apt install apktool=<VERSION_BEFORE_3.0.0> sudo apt-mark hold apktool

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list apktool sudo dnf downgrade apktool-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add apktool

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39973?

apktool: upgrade to 3.0.2. Exact commands for each OS are on this page.

Is CVE-2026-39973 being exploited?

CVE-2026-39973 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39973 affect?

CVE-2026-39973 affects apktool. Severity is high (CVSS 7.1). 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 fil

How urgent is CVE-2026-39973?

Priority 27/100. High severity

Software pages

Java vulnerabilities · Android vulnerabilities

References

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