CVE-2021-36126 json
An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36.
published 2021-07-02 5 y ago modified 2026-06-17 4 mo ago also BIT-mediawiki-2021-36126 , EUVD-2021-22758
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.
Patch / fix
- bitnami mediawiki 1.36.1
Exploit prediction
1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- phabricator.wikimedia.org https://phabricator.wikimedia.org/T284364 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| OSV | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | mediawiki | <1.36.1 |
1.36.1 |
References
-
phabricator.wikimedia.org
/T284364
exploit, issue-tracking, patch, vendor-advisory, web
-
gerrit.wikimedia.org
/r/q/I9e9f44b7663e810de70fb9ac7f6760f83dd4895b
patch, vendor-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2021-36126
web
Sources
- CVE List CVE-2021-36126
- NVD CVE-2021-36126
- OSV BIT-mediawiki-2021-36126
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.