MISP cullEmptyEvents CSRF Allows Irreversible Deletion of Events via GET Request (CVE-2026-85236) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-85236

MISP cullEmptyEvents CSRF Allows Irreversible Deletion of Events via GET Request

Answer in brief

CVE-2026-85236 records a Unknown severity vulnerability in MISP cullEmptyEvents CSRF Allows Irreversible Deletion of Events via GET Request. The current sources do not mark it as known exploited. The current feed maps misp/misp (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 3, 2026Updated Sep 3, 2026Source checked Sep 3, 2026First seen by HOL Sep 3, 2026Material review Sep 3, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps misp/misp (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
misp/mispgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for misp/misp.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 3, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.