Vulnerability · Published Apr 7, 2026 · Assigned by wikimedia-foundation
CVE-2026-39935XSS-via-i18n in localised wiki names
Medium 6.9
In plain English
A medium-severity cross-site scripting in Mediawiki - CampaignEvents Extension from The Wikimedia Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.3%top 79.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in The Wikimedia Foundation Mediawiki - CampaignEvents Extension allows Cross-Site Scripting (XSS). This issue was remediated only on the `master` branch.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The Wikimedia Foundation | Mediawiki - CampaignEvents Extension | 1.431.441.450 – before 1.43 |
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L