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MEDIUM severity

CVE-2023-22899 — zip4j

MEDIUM

CVE-2023-22899 is a medium-severity (CVSS 5.9) CWE-346 vulnerability in net.lingala.zip4j:zip4j. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for net.lingala.zip4j:zip4j — see the affected versions and patch details below.

Zip4j Origin Validation Error

Also known asGHSA-2pj2-gchf-wmw7
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
2 known
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-22899.

EPSS Exploitation Probability

via FIRST.org ↗
0.7%probability of exploitation in next 30 days
Lower Risk+0.02%
Lower risk than most CVEs52th percentile — riskier than 52% of all scored CVEsHighest risk
0.00%0.39%0.78%1.17%0.3%0.7%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
☕net.lingala.zip4j:zip4j

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a ZIP archive. This issue has been fixed in version 2.11.3.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
☕Mavennet.lingala.zip4j:zip4jall versions2.11.3net.lingala.zip4j:zip4j:2.11.3

Affected Products

1 product · 1 configurations
Application
zip4jzip4j_project
≤ 2.11.2
range
Exploits & PoCs
2

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net.lingala.zip4j:zip4j, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update net.lingala.zip4j:zip4j to 2.11.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-22899 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
ProductFixed inAdvisory
Migration Toolkit for Runtimes 1 on RHEL 8org.jboss.windup-windup-parentRHSA-2023:3814
MTA-6.2-RHEL-9mta/mta-operator-bundle:6.2.0-29RHSA-2023:4627

Frequently Asked Questions

Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a ZIP archive. This issue has been fixed in version 2.11.3.
O3 Security · Impact-Aware SCA

Is CVE-2023-22899 in your dependencies?

Find it across Maven, including transitive dependencies.

CVE-2023-22899: zip4j — Fixed in 2.11.3