Medium severity · published Sep 15, 2026
CVE-2026-91857
MISP: State-changing actions accessible via GET request enabling CSRF
5.3
CVSS
0.2%
EPSS
No
On KEV
Description
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
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MI
MISP · MISP
before 2.5.46 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91857
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91857
github.com
https://github.com/MISP/MISP/commit/b4a5486b5
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