Uncaught Exception Affecting uri-js package, versions *
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-URIJS-20341609
- published1 Oct 2026
- disclosed30 Sept 2026
- creditUnknown
Introduced: 30 Sep 2026
NewCVE-2026-103387 (opens in a new tab)How to fix?
There is no fixed version for uri-js.
Overview
uri-js is a RFC 3986/3987 compliant, scheme extendable URI/IRI parsing/validating/resolving library for JavaScript.
Affected versions of this package are vulnerable to Uncaught Exception in the parse() function of src/schemes/mailto.ts, whose to branch calls hfield[1].split(",") directly, while the subject, body, and default branches all route through unescapeComponent(), which short-circuits on a missing value. An attacker can crash the process by supplying a mailto URI whose query carries a bare to token with no =value, such as mailto:?to, so splitting on = yields a one element array and the undefined second element is dereferenced. This requires the application to pass an attacker-influenced string to URI.parse(), URI.resolve(), URI.normalize(), or URI.equal(), none of which wrap the scheme handler in a try/catch, and whether the throw terminates the process or only fails the one request depends on the host's own error handling.