CVE-2021-31550
An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2. Via crafted...
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.
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
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-31550- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - 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
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.
- Record
CVE-2021-31550- Updated
- 2026-11-02
EUVDEUVD-2021-18447 No score
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.
- Record
EUVD-2021-18447- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j4x7-chwp-xcr5 No score
An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2. Via crafted...
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.
- Record
GHSA-j4x7-chwp-xcr5- Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-31550- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVBIT-mediawiki-2021-31550 No score
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.
- Record
BIT-mediawiki-2021-31550- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mediawikiBitnami |
before 1.35.3 | 1.35.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-31550 is a medium vulnerability (CVSS 5.4) in Mediawiki, published April 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 39th percentile. Fixed in mediawiki 1.35.3.