Medium severity · published Jan 9, 2026
CVE-2026-0817
CampaignEvents API missing authorization exposes meeting and chat URLs
5.3
CVSS
0.3%
EPSS
No
On KEV
Description
Missing Authorization vulnerability in Wikimedia Foundation MediaWiki - CampaignEvents extension allows Privilege Abuse.This issue affects MediaWiki - CampaignEvents extension: 1.45, 1.44, 1.43, 1.39.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
MediaWiki - CampaignEvents extension · Wikimedia Foundation
1.45; 1.44; 1.43; 1.39 · source: vendor
CA
Campaignevents · Wikimedia
1.39; 1.43; 1.44; 1.45 · source: NVD
Affected product
MC
MediaWiki - CampaignEvents extension
Wikimedia Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-0817
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-0817
Patch
https://gerrit.wikimedia.org/r/q/I7ed0049691258c8bd2555e599b9b88490fbe3358
Issue Tracking
https://phabricator.wikimedia.org/T410560
More from MediaWiki - CampaignEvents extension
5.6
CVE-2025-53490
Multiple XSS in CampaignEvents