{"cve":"CVE-2021-42136","nvd":{"published":"2022-04-13T16:15:09.563","modified":"2026-06-17T04:09:24.537","status":"Modified","description":"A stored Cross-Site Scripting (XSS) vulnerability in the Missing Data Codes functionality of REDCap before 11.4.0 allows remote attackers to execute JavaScript code in the client's browser by storing said code as a Missing Data Code value. This can then be leveraged to execute a Cross-Site Request Forgery attack to escalate privileges to administrator.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","score":9.0},"cwes":["CWE-79"],"references":["http://packetstormsecurity.com/files/166723/REDCap-Cross-Site-Scripting.html","https://redcap.med.usc.edu/_shib/assets/ChangeLog_Standard.pdf","https://www.project-redcap.org/","http://packetstormsecurity.com/files/166723/REDCap-Cross-Site-Scripting.html","https://redcap.med.usc.edu/_shib/assets/ChangeLog_Standard.pdf"],"products":["vanderbilt:redcap"],"source":"nvd","synced_at":"2026-10-19T21:30:03.577988018+00:00"},"epss":{"cve":"CVE-2021-42136","score":0.04657,"percentile":0.91744,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}