CVE-2021-31550 json
An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2.
published 2021-04-22 5 y ago modified 2026-06-17 4 mo ago also BIT-mediawiki-2021-31550 , EUVD-2021-18447
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 39%
- public exploits
- 0
- none known
Summary
An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2. Via crafted configuration variables, a malicious actor could introduce XSS payloads into various layers.
Patch / fix
- bitnami mediawiki 1.35.3
Exploit prediction
0.45% chance of exploitation in the next 30 days, higher than 39% 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 |
| OSV | 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 |
|---|---|---|---|
| bitnami | mediawiki | <1.35.3 |
1.35.3 |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
gerrit.wikimedia.org
/r/c/mediawiki/extensions/Commentbox/+/651934/
issue-tracking, vendor-advisory, web
-
phabricator.wikimedia.org
/T270767
third-party-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2021-31550
web
Sources
- CVE List CVE-2021-31550
- NVD CVE-2021-31550
- OSV BIT-mediawiki-2021-31550
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