8.8
HIGH CVSS 4.0
CVE-2026-85236
MISP cullEmptyEvents CSRF Allows Irreversible Deletion of Events via GET Request
Description

A cross-site request forgery (CSRF) vulnerability existed in the cullEmptyEvents action of MISP. The endpoint performed a state-changing and irreversible operation while accepting HTTP GET requests. Because bodyless GET requests are not subject to CakePHP's CSRF validation, an attacker could cause an authenticated MISP user with sufficient privileges to invoke the endpoint simply by causing their browser to load a crafted URL, for example through an embedded image or other automatically requested resource. Successful exploitation triggers the deletion of published empty events. The deletion is particularly significant because the operation uses skipBlocklist, meaning the removed events do not leave blocklist entries that could prevent or track their subsequent synchronization. This can result in unintended and potentially irreversible deletion of MISP event records without explicit user interaction. The vulnerability was addressed by restricting cullEmptyEvents to HTTP POST requests, ensuring that CakePHP's normal CSRF protections are applied to the operation.

INFO

Published Date :

Sept. 3, 2026, 4:18 p.m.

Last Modified :

Sept. 3, 2026, 4:45 p.m.

Remotely Exploit :

Yes !

Source :

5a6e4751-2f3f-4070-9419-94fb35b644e8
Affected Products

The following products are affected by CVE-2026-85236 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Misp-project misp
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS 4.0 HIGH 5a6e4751-2f3f-4070-9419-94fb35b644e8
Solution
Restrict state-changing actions to POST requests to enable CSRF protection.
  • Update the application to only accept POST requests for sensitive actions.
  • Ensure CSRF validation is enabled for all state-changing operations.
  • Review application logic for unintended GET request vulnerabilities.
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-2026-85236.

URL Resource
https://github.com/MISP/MISP/commit/2b6b3ac90
https://github.com/MISP/MISP/commit/50106c9a0
https://github.com/MISP/MISP/commit/66ecb5acb
https://github.com/MISP/MISP/commit/9c1346ce1
https://github.com/MISP/MISP/commit/cfc8b8a6d
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-85236 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-2026-85236 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-2026-85236 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-85236 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.

  • New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8

    Sep. 03, 2026

    Action Type Old Value New Value
    Added Description A cross-site request forgery (CSRF) vulnerability existed in the cullEmptyEvents action of MISP. The endpoint performed a state-changing and irreversible operation while accepting HTTP GET requests. Because bodyless GET requests are not subject to CakePHP's CSRF validation, an attacker could cause an authenticated MISP user with sufficient privileges to invoke the endpoint simply by causing their browser to load a crafted URL, for example through an embedded image or other automatically requested resource. Successful exploitation triggers the deletion of published empty events. The deletion is particularly significant because the operation uses skipBlocklist, meaning the removed events do not leave blocklist entries that could prevent or track their subsequent synchronization. This can result in unintended and potentially irreversible deletion of MISP event records without explicit user interaction. The vulnerability was addressed by restricting cullEmptyEvents to HTTP POST requests, ensuring that CakePHP's normal CSRF protections are applied to the operation.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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/2026/85xxx/CVE-2026-85236.json">CVE-2026-85236</a>
    Added Reference https://github.com/MISP/MISP/commit/2b6b3ac90
    Added Reference https://github.com/MISP/MISP/commit/50106c9a0
    Added Reference https://github.com/MISP/MISP/commit/66ecb5acb
    Added Reference https://github.com/MISP/MISP/commit/9c1346ce1
    Added Reference https://github.com/MISP/MISP/commit/cfc8b8a6d
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.