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
What this means for your business
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 11% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- Not yet scored
- CVSS v4
- 5.3
- Weakness
- CWE-352
- Assigned by
- 5a6e4751-2f3f-4070-9419-94fb35b644e8
Dates
- Published
- 2026-09-15
- Last modified
- 2026-09-15
- Sources
- NVD