CVE-2026-0817

CampaignEvents API missing authorization exposes meeting and chat URLs

5.3 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: None
Availability: None

Exploit likelihood

0.27%Up 0.2 points since Jan 10, 2026

What each source reports

CVE List Score used 5.3

CampaignEvents API missing authorization exposes meeting and chat URLs

Record: CVE-2026-0817
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-862
Updated: 2026-11-02

EUVDEUVD-2026-1726 5.3

Record: EUVD-2026-1726
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-5v56-6x55-vhpv 5.3

Missing Authorization vulnerability in Wikimedia Foundation MediaWiki - CampaignEvents extension...

Record: GHSA-5v56-6x55-vhpv
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-862
Updated: 2026-11-02

NVD 5.3

Record: CVE-2026-0817
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-862
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-0817 is a medium vulnerability (CVSS 5.3) in The Wikimedia Foundation Mediawiki - Campaignevents Extension, published January 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 19th percentile. No source names a fixed version.