CVE-2025-23210
CVE-2025-23210 is a Cross-site Scripting (XSS) vulnerability in phpoffice/phpspreadsheet. O3 Security confirms whether CVE-2025-23210 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Bypass XSS sanitizer using the javascript protocol and special characters in phpoffice/phpspreadsheet
Blast Radius
phpoffice/phpspreadsheet🐘phpoffice/phpspreadsheet🐘phpoffice/phpspreadsheet🐘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
phpoffice/phpspreadsheet is a pure PHP library for reading and writing spreadsheet files. Affected versions have been found to have a Bypass of the Cross-site Scripting (XSS) sanitizer using the javascript protocol and special characters. This issue has been addressed in versions 3.9.0, 2.3.7, 2.1.8, and 1.29.9. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpoffice/phpspreadsheet | ≥ 3.0.0&&< 3.9.0 | 3.9.0 |
| 🐘Packagist | phpoffice/phpspreadsheet | all versions | 1.29.9 |
| 🐘Packagist | phpoffice/phpspreadsheet | ≥ 2.2.0&&< 2.3.7 | 2.3.7 |
| 🐘Packagist | phpoffice/phpspreadsheet | ≥ 2.0.0&&< 2.1.8 | 2.1.8 |
| 🐘Packagist | phpoffice/phpexcel | all versions | No fix |
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 3.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-23210 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 CVE-2025-23210 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 CVE-2025-23210. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-23210 in your dependencies?
O3 detects CVE-2025-23210 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.