CVE-2026-23907
📋 TL;DR
This CVE describes a path traversal vulnerability in Apache PDFBox's ExtractEmbeddedFiles example code. Attackers can exploit this to write files outside the intended extraction directory, potentially overwriting critical system files. Only users who have copied this specific example code into their production applications are affected.
💻 Affected Systems
- Apache PDFBox
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary file overwrite leading to system compromise, denial of service, or data corruption by writing to sensitive system locations.
Likely Case
Local file overwrite within the application's directory structure, potentially causing application instability or data loss.
If Mitigated
Contained to application's sandboxed directory with proper file permission restrictions.
🎯 Exploit Status
Exploitation requires the application to process malicious PDF files with embedded files using the vulnerable example code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.36, 3.0.7
Vendor Advisory: https://lists.apache.org/thread/gyfq5tcrxfv7rx0z2yyx4hb3h53ndffw
Restart Required: No
Instructions:
1. Update Apache PDFBox to version 2.0.36 or 3.0.7. 2. If you copied the ExtractEmbeddedFiles example, replace it with the updated version from the patched release. 3. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Implement path validation
allAdd canonical path validation before file extraction to prevent directory traversal
// Java code: Validate extraction path contains base directory
Path basePath = Paths.get(baseDir).toAbsolutePath().normalize();
Path targetPath = Paths.get(baseDir, fileName).toAbsolutePath().normalize();
if (!targetPath.startsWith(basePath)) { throw new SecurityException("Path traversal attempt"); }
🧯 If You Can't Patch
- Review all uses of ExtractEmbeddedFiles example code and implement manual path validation
- Restrict file system permissions for the application to prevent writes outside its directory
🔍 How to Verify
Check if Vulnerable:
Search your codebase for uses of ExtractEmbeddedFiles example or PDComplexFileSpecification.getFilename() without proper path validationCheck Version:
Check Maven/Gradle dependencies for PDFBox version, or run: java -cp pdfbox-app.jar org.apache.pdfbox.VersionVerify Fix Applied:
Test with malicious PDF containing embedded files with path traversal sequences (e.g., '../../etc/passwd') to ensure extraction fails📡 Detection & Monitoring
Log Indicators:
- Failed file extraction attempts with suspicious path patterns
- Security exceptions from path validation
Network Indicators:
- Unusual PDF file uploads to applications using PDFBox
SIEM Query:
source="application_logs" AND ("ExtractEmbeddedFiles" OR "PDComplexFileSpecification") AND ("..\\" OR "../" OR "%2e%2e")