What’s Vulnerable › Vulnerabilities

CVE-2026-54550: IzPack: Path Traversal in UnpackerBase allows writing files outside the installation directory via malicious pack entries

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-26 · updated 2026-09-09
• Weakness: CWE-22

Description

IzPack is a widely used tool for packaging applications on the Java platform as cross-platform installers. In 5.2.6 and earlier, UnpackerBase.unpack() in izpack-installer/src/main/java/com/izforge/izpack/installer/unpacker/UnpackerBase.java obtains an attacker-controlled PackFile targetPath, passes it through IoHelper.translatePath(), which only converts separators, and constructs a File without normalizing parent-directory segments or enforcing destination containment. A malicious installer pack entry containing ../ sequences can therefore write outside the intended installation directory to startup folders, executable search paths, or other locations accessible with the victim's privileges when the victim runs the installer.

Affected products

• izpack: through 5.2.6

References

• https://github.com/izpack/izpack/commit/4233ba38d0f1825f9cf3e0204e5261a5498e29d8
• https://github.com/izpack/izpack/commit/8b7c6792c4fe85e3b1759c106aae39b904848466
• https://github.com/izpack/izpack/pull/1193
• https://github.com/izpack/izpack/security/advisories/GHSA-f63g-88cj-hjf9
• https://github.com/izpack/izpack/security/advisories/GHSA-f63g-88cj-hjf9

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