CVE-2021-42136
A stored Cross-Site Scripting (XSS) vulnerability in the Missing Data Codes Functionality of...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-42136- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-42136- Updated
- 2026-11-02
EUVDEUVD-2021-29119 No score
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.
- Record
EUVD-2021-29119- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-q99w-xr78-49hh
A stored Cross-Site Scripting (XSS) vulnerability in the Missing Data Codes Functionality of...
A stored Cross-Site Scripting (XSS) vulnerability in the Missing Data Codes Functionality of REDCap 11.2.5 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.
- Record
GHSA-q99w-xr78-49hh- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | REDCap 11.3.9 - Stored Cross Site Scripting | 2022-04-19 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, Exploit-DB, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-42136 is a critical vulnerability (CVSS 9.0) in Vanderbilt Redcap, published April 13, 2022. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 4.66%, the 91st percentile. No source names a fixed version.