Medium severity · published Sep 25, 2026
CVE-2026-100376
TemplateSandbox can be abused for XSS by asking another user to preview a page with a certain sandbox prefix
4.8
CVSS
0.3%
EPSS
No
On KEV
Description
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - TemplateSandbox Extension allows Cross-Site Scripting (XSS).
This issue affects Mediawiki - TemplateSandbox Extension: from * before 1.46.1, 1.45.5, 1.43.10.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MT
Mediawiki - TemplateSandbox Extension · Wikimedia Foundation
before 1.46.1, 1.45.5, 1.43.10 · source: vendor
Affected product
MT
Mediawiki - TemplateSandbox Extension
Wikimedia Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-100376
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-100376
gerrit.wikimedia.org
https://gerrit.wikimedia.org/r/q/I6630b9915f640bf75c8570165eb8728bd7a2c07a
phabricator.wikimedia.org
https://phabricator.wikimedia.org/T430596
More from Mediawiki - TemplateSandbox Extension
9.1
CVE-2026-100240
TemplateSandbox does not check read permissions for the page being previewed