CVE-2021-30157 json
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2.
published 2021-04-06 5 y ago modified 2026-06-17 4 mo ago also BIT-mediawiki-2021-30157 , EUVD-2021-17093
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.4%
- EPSS 1.4% chance of exploitation in 30 days, percentile 72%
- public exploits
- 0
- none known
Summary
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On ChangesList special pages such as Special:RecentChanges and Special:Watchlist, some of the rcfilters-filter-* label messages are output in HTML unescaped, leading to XSS.
Patch / fix
- bitnami mediawiki 1.31.12, 1.35.2
- mediawiki mediawiki 1.31.12, 1.35.2
- mediawiki Debian 14, Debian 13, Debian 12 1:1.35.2-1
debian advisories DEBIAN-CVE-2021-30157
- mediawiki Arch Linux 1.35.2-1
arch linux advisories AVG-1775
- phabricator.wikimedia.org/T278058 advisory
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2021-30157 updated cvss 6.1
mediawiki: XSS due to unescaped messages used in HTML on ChangesList pages
-
Red Hat OpenShift Container Platform 3.11 mediawikiaffected: no fix planned “Will not fix”
-
Red Hat OpenShift Container Platform 4 mediawikiaffected: no fix planned “Out of support scope”
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
1.41% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- phabricator.wikimedia.org https://phabricator.wikimedia.org/T278058 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
| OSV | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | mediawiki | <1.31.12 >=1.32.0, <1.35.2 |
1.31.12 1.35.2 |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
phabricator.wikimedia.org
/T278058
exploit, issue-tracking, patch, vendor-advisory, web
-
debian.org
/security/2021/dsa-4889
vendor-advisory, third-party-advisory, web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
vendor-advisory, web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
vendor-advisory, web
-
security.gentoo.org
/glsa/202107-40
vendor-advisory, third-party-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2021-30157
web
Sources
- CVE List CVE-2021-30157
- NVD CVE-2021-30157
- OSV BIT-mediawiki-2021-30157
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.