react-signature-canvas is a small, popular React wrapper around the signature_pad library for capturing handwritten signatures on an HTML canvas, and while it carries no known direct vulnerability, its inactive maintenance status and the way applications handle the captured image are what deserve your attention. The component is under 150 lines, widely downloaded, and stable, but "stable and unmaintained" is a specific risk profile worth reasoning about before it lands in a document-signing or onboarding flow.
What react-signature-canvas does
The package, maintained by Adam Gilgur, wraps signature_pad in a React component. You drop it into a form, the user draws a signature with a mouse or finger on a <canvas>, and you read the result out as a data URL, typically a base64-encoded PNG:
const sigRef = useRef();
// ...
const dataUrl = sigRef.current.toDataURL("image/png");
That image then usually gets sent to a server, stored, and rendered back later, often in a legal or compliance context like a signed agreement. That lifecycle, capture then store then re-render, is where the security thinking belongs, because the component itself only draws pixels.
Maintenance status: inactive but not abandoned
The maintenance status of react-signature-canvas is inactive. It has not published a new version to npm in some time, the latest release being a 1.1.0-alpha.2 from early 2025, though the GitHub repository still sees occasional community interaction. At the same time it is genuinely popular, drawing well over half a million npm downloads a week.
That combination, high usage, low maintenance, is common for small "does one thing" packages and is not automatically disqualifying. A 150-line wrapper has little surface for bugs to hide in, and its core dependency, signature_pad, is maintained separately. But inactive maintenance means that if a problem does surface, or if a future React version breaks the component, you may be waiting on a fix that does not come quickly. Factor that into the decision the same way you would for any low-bus-factor dependency.
Known vulnerabilities
Advisory databases do not list a direct vulnerability in react-signature-canvas itself as of this review. That is the honest picture, and it is reassuring for a component handling something as sensitive as signatures.
As always, "no direct advisory" is not the whole story. The package depends on signature_pad, which has its own version history, and your build pulls in a transitive tree beneath both. The risk you actually inherit is the union of all of it. Running a dependency scan across the full tree, rather than eyeballing your direct dependencies, is what turns "probably fine" into "verified." An SCA tool resolves that subtree and flags any known issue in signature_pad or below.
The real risk is how you handle the output
The vulnerability class to watch is not in the canvas drawing, it is cross-site scripting (XSS) in the handling of the captured image. The component hands you a data URL. If your application ever takes user-influenced data associated with that signature, a filename, a note field, a metadata string, and injects it into the DOM without encoding, you have an XSS hole that has nothing to do with the signature widget but sits right next to it in the same form.
Two concrete precautions:
Treat the data URL as untrusted input on the server. Validate that it is actually an image of the expected MIME type and within a size limit before storing it, rather than trusting the image/png prefix the client sent. A client can send any string in that field.
Never render user-controlled strings from the signing flow with dangerouslySetInnerHTML. React escapes text by default, which protects you, so the danger is specifically the escape hatches. Keep the signature image in an <img src={dataUrl}> and let React handle the rest.
Safe usage checklist
- Pin the version in your lockfile and scan the full dependency subtree, including signature_pad, in CI.
- Validate the captured image server-side: real image, expected type, size-capped.
- Store signatures with the same care as any personal data, encryption at rest and access controls, since they are often legally significant.
- Watch the repository's activity. If it stays inactive and a React major version breaks it, have a migration target in mind.
- Avoid
dangerouslySetInnerHTMLanywhere in the signing flow.
The Safeguard Academy covers building this kind of per-dependency risk checklist so the review is repeatable rather than ad hoc.
FAQ
Is react-signature-canvas safe to use?
There is no known direct vulnerability in it, and its small size limits the room for bugs. The caveats are its inactive maintenance status and that most real risk comes from how your application validates and renders the captured signature, not from the component itself.
Is react-signature-canvas still maintained?
Its maintenance status is inactive, with no recent npm release, though the GitHub repository still sees occasional community activity. It remains very popular by download count. Treat it as a low-maintenance dependency and keep a migration path in mind.
What is the main security risk with react-signature-canvas?
Handling of the captured image. Validate the returned data URL server-side as a real, size-limited image rather than trusting the client, and never inject user-controlled strings from the signing flow into the DOM with dangerouslySetInnerHTML, which is the XSS risk to avoid.
How should I store captured signatures?
As sensitive personal data: encrypt at rest, restrict access, and validate the image on upload. Signatures are frequently legally significant, so apply the same controls you would to other regulated data.