Medium severity · published Apr 7, 2026
CVE-2026-39840
CSS injection in multiple Cargo display formats
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension allows XSS Targeting Non-Script Elements.This issue affects Mediawiki - Cargo Extension: before 3.8.7.
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 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
Mediawiki - Cargo Extension · Wikimedia Foundation
before 3.8.7 · source: vendor
CA
Cargo · Mediawiki
before 3.8.7 · source: NVD
Affected product
MC
Mediawiki - Cargo Extension
Wikimedia Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39840
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-39840
Patch
https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Cargo/+/1237966
Exploit
https://phabricator.wikimedia.org/T416368
More from Mediawiki - Cargo Extension
6.1
CVE-2026-39841
Stored XSS through list fields on Cargo's page values and Special:CargoTables
6.1
CVE-2026-39839
Stored XSS through URLs in Cargo's map format
5.4
CVE-2026-39837
Stored XSS through the dynamic table format in Cargo