Sploitus

Exploit for CVE-2026-21509

kitploit · 2026-09-09

Exploit Code

MARKDOWN16 lines
## https://sploitus.com/exploit?id=KITPLOIT:TOOLS-GITHUB-SENTINEL-AIDEFENSE-CVE-2026-21509
# CVE-2026-21509 — Microsoft Office OLE Security-Feature Bypass

![CVE](https://img.shields.io/badge/CVE-2026--21509-red.svg) ![CVSS](https://img.shields.io/badge/CVSS%203.1-7.8%20High-orange.svg) ![CWE](https://img.shields.io/badge/CWE-807-blue.svg) ![CISA KEV](https://img.shields.io/badge/CISA-KEV%20listed-darkred.svg) ![Status](https://img.shields.io/badge/exploited-in%20the%20wild-critical.svg)

> Research writeup by **Sentinel AI Defense**. Defensive analysis only — no working exploit or PoC is published here for an actively exploited vulnerability.

A security-feature bypass in Microsoft Office that lets a crafted document load COM components the OLE mitigations are supposed to block. Actively exploited by **APT28 (UAC-0001)** against Ukrainian and Eastern European targets.

📄 Full writeup: https://sentinelaidefense.com/posts/cve-2026-21509-ole-bypass

* * *

## Overview

CVE-2026-21509 is a security feature bypass vulnerability in Microsoft Office stemming from reliance on untrusted inputs in a security decision (CWE-807). It permits an unauthorized attacker to bypass OLE mitigations locally when a user opens a specially crafted document. The flaw affects processing of embedded objects, notably allowing instantiation of COM components that security controls are intended to restrict.