CVE-2021-43942

Name: CVE-2021-43942
Creator: NVD / NIST
Published: 2022-01-04T03:15:07.233+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 55.36%

Last modified Jun 17, 2026

CVE-2021-43942 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Affected versions of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a Reflected Cross-Site Scripting (XSS) vulnerability in the /rest/collectors/1.0/template/custom endpoint. To exploit this issue, the attacker must trick a user into visiting a malicious website. EPSS estimates a 55.36% chance of exploitation in the next 30 days.

Description

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a Reflected Cross-Site Scripting (XSS) vulnerability in the /rest/collectors/1.0/template/custom endpoint. To exploit this issue, the attacker must trick a user into visiting a malicious website. The affected versions are before version 8.13.15, and from version 8.14.0 before 8.20.3.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

55.36%

98.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Atlassian	Jira Server	>= 8.14.0, < 8.20.3
Atlassian	Jira Server And Data Center	< 8.13.5

References

https://jira.atlassian.com/browse/JRASERVER-73068Issue Tracking, Vendor Advisory
https://jira.atlassian.com/browse/JRASERVER-73068Issue Tracking, Vendor Advisory

Timeline

Published: Jan 4, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43942?

How severe is CVE-2021-43942?

CVE-2021-43942 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 55.36% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43942?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43942?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST