CVE-2026-33137: XWiki XWiki-Platform

Critical severity, CVSS 9.3. EPSS: 0.9% chance of exploitation in the next 30 days.

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. XWiki Platform is a generic wiki platform. In versions starting with 15.10.6 and prior to 18.1.0-rc-1, 17.10.3, 17.4.9, and 16.10.17, the POST /wikis/{wikiName} API executes a XAR import without performing any authentication or authorization checks, allowing an unauthenticated attacker to create or update documents in the target wiki. This vulnerability has been patched in XWiki 16.10.17, 17.4.9, 17.10.3, 18.0.1 and 18.1.0-rc-1.

Affected products

• XWiki XWiki-Platform: from 15.10.6, before 16.10.17 (fixed in 16.10.17); from 17.0.0-rc-1, before 17.4.9 (fixed in 17.4.9); from 17.5.0, before 17.10.3 (fixed in 17.10.3); from 18.0.0-rc-1, before 18.1.0-rc-1 (fixed in 18.1.0-rc-1)

Published 2026-05-20. Last modified 2026-07-23.