CVE-2026-91857
MISP: State-changing actions accessible via GET request enabling CSRF
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
INFO
Published Date :
Sept. 15, 2026, 10:17 a.m.
Last Modified :
Sept. 16, 2026, 1:42 p.m.
Remotely Exploit :
Yes !
Source :
5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | MEDIUM | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | ||||
| CVSS 4.0 | MEDIUM | 5a6e4751-2f3f-4070-9419-94fb35b644e8 |
Solution
- Update MISP to version 2.5.46 or later.
- Verify UI requests use POST for purgeUnusedPictures.
- Ensure CSRF token validation is enabled for AJAX actions.
- Apply controller patches to restrict actions to POST.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-91857.
| URL | Resource |
|---|---|
| https://github.com/MISP/MISP/commit/b4a5486b5 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-91857 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-91857
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-91857 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-91857 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 15, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-91857', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-15T13:10:25.729586Z'} -
New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8
Sep. 15, 2026
Action Type Old Value New Value Added 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 Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-352 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/91xxx/CVE-2026-91857.json">CVE-2026-91857</a> Added Reference https://github.com/MISP/MISP/commit/b4a5486b5