CVE-2026-100383: Wikimedia Foundation Mediawiki – WikiLambda Extension · XSS or 'Cross-site Scripting'
Affects Wikimedia Foundation Mediawiki – WikiLambda ExtensionSource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium · patch available : update Wikimedia Foundation Mediawiki – WikiLambda Extension when convenient.
Data as of 9 Nov 2026, 23:24 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Wikimedia FoundationMediawiki - WikiLambda Extension | Affected
| Fixed in– |
GitHubwikimedia/mediawiki/extensions/WikiLambdapkg:github/wikimedia/mediawiki/extensions/WikiLambdaOther threats | Affected
| Fixed in– |
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AI-suggested
A patch is available and the issue has been remediated in the master branch of the WikiLambda Extension. Users of version 1.47.0-alpha should update to the fixed version as soon as it is released. Since this is a cloud service, the Wikimedia Foundation manages remediation for hosted instances; users should verify that their deployments are updated accordingly.
Description
A Cross-Site Scripting (XSS) vulnerability exists in the Wikimedia Foundation Mediawiki WikiLambda Extension version 1.47.0-alpha. This vulnerability is due to improper neutralization of input during web page generation, which could allow an attacker to inject malicious scripts. The issue has been fixed in the master branch of the codebase.