GHSA-wc29-h54q-q8qx is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in formstone. A fix is available for formstone — see the affected versions and patch details below.
Formstone Vulnerable to Reflected XSS
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-wc29-h54q-q8qx plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
formstonenpmDescription
Formstone <=1.4.16 is vulnerable to a Reflected Cross-Site Scripting (XSS) vulnerability caused by improper validation of user supplied input in the upload-target.php and upload-chunked.php files. A remote attacker could exploit this vulnerability using a specially crafted URL to execute a script in a victim's Web browser within the security context of the hosting Web site once the URL is clicked or visited. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials, force malware execution, user redirection and others.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | formstone | all versions | 1.4.17npm install formstone@1.4.17 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for formstone, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update formstone to 1.4.17 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wc29-h54q-q8qx 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-wc29-h54q-q8qx can be triaged on real exposure rather than presence alone.
Tailored to GHSA-wc29-h54q-q8qx. 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-wc29-h54q-q8qx in your dependencies?
O3 Security finds GHSA-wc29-h54q-q8qx across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.