CVE-2020-35478 json
MediaWiki before 1.35.1 allows XSS via BlockLogFormatter.php.
published 5y ago modified 4mo ago also BIT-mediawiki-2020-35478 , EUVD-2020-23149
- 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
MediaWiki before 1.35.1 allows XSS via BlockLogFormatter.php. MediaWiki:blanknamespace potentially can be output as raw HTML with SCRIPT tags via LogFormatter::makePageLink(). This affects MediaWiki 1.33.0 and later.
Patch / fix
- bitnami mediawiki 1.35.1
- mediawiki mediawiki 1.35.1
- mediawiki Debian 14, Debian 13, Debian 12 1:1.35.1-1
debian advisories DEBIAN-CVE-2020-35478
- mediawiki Arch Linux 1.35.1-1
arch linux advisories AVG-1371
Is CVE-2020-35478 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2020-35478 updated cvss 6.1
mediawiki: potential XSS via MediaWiki:blanknamespace outputting Block Logs
-
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
1.37% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- phabricator.wikimedia.org https://phabricator.wikimedia.org/T268938 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 | >=1.33.0, <1.35.1 |
1.35.1 |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
phabricator.wikimedia.org
/T268938
exploit, third-party-advisory, web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/STT5Z4A3BCXVH3WIPICWU2FP4IPIMUPC/
vendor-advisory, web
-
lists.wikimedia.org
/pipermail/mediawiki-announce/2020-December/000268.html
mailing-list, release-notes, vendor-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2020-35478
web
Sources
- CVE List CVE-2020-35478
- NVD CVE-2020-35478
- OSV BIT-mediawiki-2020-35478
Fencer Intel 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.