CVE-2026-91857
Affected versions of MISP expose several state-changing controller actions without restricting them to POST. The affected actions are: - EventReportsController::purgeUnusedPictures() - NoticelistsController::enableNoticelist() - ServersController::removeOrphanedCorrelations() - WorkflowsController::rebuildRedis() The patch adds allowMethod(['post']) to each action, preventing them from being triggered through ordinary GET requests. For purgeUnusedPictures(), the corresponding UI previously used $.get(). The fix converts that request to POST and supplies X-CSRF-Token, while the controller enables header-only CSRF validation for that AJAX action. Because GET requests can be induced cross-origin through links, images, redirects, or navigation, accepting GET for these state-changing operations can let an attacker trigger them using the authenticated victim's session. Version affected: ≤2.5.45
- Published Sep 15, 2026
- CVSS 5.3 medium
- 0.2% chance of exploitation in the next 30 days (EPSS)
- A fix is available