CVE-2021-21660 json
XSS vulnerability in Jenkins Markdown Formatter Plugin
published 2021-05-25 5 y ago modified 2026-06-17 4 mo ago also GHSA-xqpp-26pp-2365 , EUVD-2022-5842
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
Summary
Jenkins Markdown Formatter Plugin 0.1.0 and earlier does not sanitize crafted link target URLs, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with the ability to edit any description rendered using the configured markup formatter.
Patch / fix
- maven io.jenkins.plugins:markdown-formatter 0.2.0
Exploit prediction
1.09% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | io.jenkins.plugins:markdown-formatter | <0.2.0 |
0.2.0 |
Affected products
- Jenkins project Jenkins Markdown Formatter Plugin
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/jenkinsci/markdown-formatter-plugin/commit/6b283a5bba3424fd5174b92e7ad8724cdbdf596c
web
-
jenkins.io
/security/advisory/2021-05-25/#SECURITY-2198
web, vendor-advisory
-
whitesourcesoftware.com
/vulnerability-database/CVE-2021-21660
web, third-party-advisory
-
openwall.com
/lists/oss-security/2021/05/25/3
mailing-list, web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-21660
advisory
-
github.com
/jenkinsci/markdown-formatter-plugin
package
Sources
- CVE List CVE-2021-21660
- GitHub Advisory GHSA-xqpp-26pp-2365
- NVD CVE-2021-21660
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