Is CVE-2026-63436 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-63436 being exploited in the wild.

How severe is CVE-2026-63436?

High severity, with a CVSS score of 8.2, published 3 November 2026.

Which products and versions are affected?

org.zeroturnaround:zt-zip (Maven) < 1.18.0, ECOSYSTEM:introduced=0,fixed=1.18.0; ZeroTurnaround Zt-Zip before 1.18.0.

Is there a fix for CVE-2026-63436?

Yes. org.zeroturnaround:zt-zip (Maven): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-63436 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-63436?

Check whether you run org.zeroturnaround:zt-zip (Maven) or ZeroTurnaround Zt-Zip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-63436: zt-zip directory traversal in fluent API unpack

Q: Is there a fix for CVE-2026-63436?

Yes. org.zeroturnaround:zt-zip (Maven): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-63436 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-63436?

Check whether you run org.zeroturnaround:zt-zip (Maven) or ZeroTurnaround Zt-Zip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-63436 · Severity: high · CVSS 8.2 · Published 2026-11-03

zt-zip is a Java library for manipulating ZIP archives. The fluent API for unpacking archives does not properly validate destination paths for malicious ZIP entries, allowing an attacker to write files outside the intended extraction directory when processing untrusted archives. This could result in arbitrary file writes on the system.

Technologies: org.zeroturnaround:zt-zip (Maven). Vendors: Maven.

Quick answers

Is CVE-2026-63436 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-63436 being exploited in the wild.
How severe is CVE-2026-63436?: High severity, with a CVSS score of 8.2, published 3 November 2026.
Which products and versions are affected?: org.zeroturnaround:zt-zip (Maven) < 1.18.0, ECOSYSTEM:introduced=0,fixed=1.18.0; ZeroTurnaround Zt-Zip before 1.18.0.
Is there a fix for CVE-2026-63436?: Yes. org.zeroturnaround:zt-zip (Maven): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-63436 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-63436?: Check whether you run org.zeroturnaround:zt-zip (Maven) or ZeroTurnaround Zt-Zip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

org.zeroturnaround:zt-zip (Maven): upgrade to 1.18.0 or later

# set org.zeroturnaround:zt-zip to 1.18.0 in your pom.xml or build.gradle

Technical details

The Zips.get(zip).unpack().destination(outputDir).process() fluent API constructs output file paths directly from ZIP entry names without applying path traversal validation. Entries with directory traversal sequences (e.g., "../") can escape the destination directory via both file copy and ZipEntryTransformer branches. The separate ZipUtil.unpack() method properly validates paths using checkDestinationFileForTraversal, which the fluent API lacks.

Affected products

ZeroTurnaround zt-zip before 1.18.0

Identifiers

CVE-2026-63436
GHSA-52c6-99qm-3hqr

Timeline

2026-11-03: disclosed

References

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