How severe is CVE-2021-42136?

CVE-2021-42136 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42136 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42136?

CVE-2021-42136 affects Vanderbilt Redcap. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42136?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-42136 published?

CVE-2021-42136 was published on 2022-04-13 and last updated on 2026-06-17.

CVE-2021-42136

CVE-2021-42136 is a critical-severity vulnerability in Vanderbilt Redcap with a CVSS 3.x base score of 9.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.0)
CVSS v2: 3.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Vanderbilt Redcap
Published: 2022-04-13
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-42136?: 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.
How severe is CVE-2021-42136?: CVE-2021-42136 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42136 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42136?: CVE-2021-42136 affects Vanderbilt Redcap. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42136?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-42136 published?: CVE-2021-42136 was published on 2022-04-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:vanderbilt:redcap:*:*:*:*:*:*:*:*

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