GHSA-xcrg-29h7-h4cj is a high-severity (CVSS 8.8) CWE-91 vulnerability in phpoffice/phpspreadsheet. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-xcrg-29h7-h4cj is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XXE in PHPSpreadsheet due to encoding issue
Real-World Exposure
phpoffice/phpspreadsheet🐘phpoffice/phpexcelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
securityScan() in PHPOffice PhpSpreadsheet through 1.5.0 allows a bypass of protection mechanisms for XXE via UTF-7 encoding in a .xlsx file
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpoffice/phpspreadsheet | all versions | 1.5.1 |
| 🐘Packagist | phpoffice/phpexcel | all versions | 1.8.2 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
PhpSpreadsheet < 1.5.0 - XML External Entity (XXE)
by Alex Leahu · Nov 30, 2018
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpoffice/phpspreadsheet. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update phpoffice/phpspreadsheet to 1.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xcrg-29h7-h4cj is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether GHSA-xcrg-29h7-h4cj is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xcrg-29h7-h4cj. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xcrg-29h7-h4cj in your dependencies?
O3 detects GHSA-xcrg-29h7-h4cj across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.