Medium severity · published Sep 29, 2026
CVE-2026-100238
Flow colon-separator and flow-guidedtour-optin-welcome-description messages allow stored XSS
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - Flow Extension allows Stored XSS.
This issue affects Mediawiki - Flow Extension: from * before 1.46.1, 1.45.5, 1.43.10.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MF
Mediawiki - Flow Extension · Wikimedia Foundation
before 1.46.1, 1.45.5, 1.43.10 · source: vendor