Vulnerability · Published Oct 26, 2026 · Assigned by GitHub_M
CVE-2026-116582Seroval: Script injection through RegExp sources in serialized output
Medium 4.7
In plain English
A medium-severity cross-site scripting in seroval from lxsmnsyc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | seroval | 1.6.10 | GHSA-9wx9-5pv9-3349 |
| npm | seroval | 1.0.0 | GHSA-9wx9-5pv9-3349 |
Affected products (as reported)
Weakness: CWE-79, CWE-116 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N