Vulnerability · Published May 20, 2026 · Assigned by VulnCheck

CVE-2026-47099TeleJSON < 6.0.0 DOM-based XSS via parse() Function

Medium 6.1

In plain English

A medium-severity cross-site scripting in telejson from storybookjs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.4%top 70.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

TeleJSON prior to 6.0.0 contains a DOM-based cross-site scripting vulnerability in the parse() function that allows attackers to execute arbitrary JavaScript by delivering a crafted JSON payload containing a malicious _constructor-name_ property value. The custom reviver passes the constructor name directly to new Function() without sanitization when recreating object prototypes, enabling attackers to inject arbitrary JavaScript through vectors such as postMessage in cross-frame communication contexts to achieve script execution within the application.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	telejson	6.0.0	GHSA-ccgf-5rwj-j3hv

Affected products (as reported)

Vendor	Product	Versions
storybookjs	telejson	0 – before 6.0.0

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

https://github.com/storybookjs/telejson/security/advisories/GHSA-ccgf-5rwj-j3hv vendor-advisory
https://github.com/Niccolo10/Security-Advisories/blob/main/CVE-2026-47099/cve-2026-47099.md technical-description
https://www.vulncheck.com/advisories/telejson-dom-based-xss-via-parse-function third-party-advisory