Microsoft Office zero-day lets malicious documents slip past security checks


Microsoft issued an emergency patch for a high-severity zero-day vulnerability in Office that allows attackers to bypass document security checks and is being exploited in the wild via malicious files.

Microsoft pushed the emergency patch for the zero‑day, tracked as CVE-2026-21509, and classified it as a “Microsoft Office Security Feature Bypass Vulnerability” with a CVSS score of 7.8 out of 10. The flaw allows attackers to bypass Object Linking and Embedding (OLE) mitigations that are designed to block unsafe COM/OLE controls inside Office documents. This means a malicious attachment could infect a PC despite built-in protections.

Read more…
Source: Malwarebytes Labs


Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox


Related:

  • Hack Breaks PDF Encryption, Opens Content to Attackers

    October 2, 2019

    Researchers in Germany have invented a new hack that can allow someone to break the encryption of PDF files and access their content  — or even forge signed PDF files under certain circumstances. A team from Ruhr University Bochum, FH Münster University of Applied Sciences and Hackmanit GmbH developed the attack, called PDFex, that can allow an attacker to view the ...

  • Securing the Industrial Internet of Things: Addressing IIoT Risks in Healthcare

    October 2, 2019

    The constant quest for prolonging and preserving human life has continually driven technologies to develop groundbreaking innovations in the delivery of healthcare services and state-of-the-art treatments. Like in many other enterprises, the industrial internet of things (IIoT) has rapidly transformed the network and data infrastructure in health and medicine. With the IIoT, medical data and information have ...

  • FDA Warns Against URGENT/11 Vulnerabilities Affecting Medical Devices and Hospital Networks

    October 1, 2019

    The U.S. Food and Drug Administration (FDA) is informing patients, health care providers and facility staff, and manufacturers about cybersecurity vulnerabilities that may introduce risks for certain medical devices and hospital networks. The FDA is not aware of any confirmed adverse events related to these vulnerabilities. However, software to exploit these vulnerabilities is already publicly ...

  • Critical Vulnerability in Harbor Enables Privilege Escalation from Zero to Admin (CVE-2019-16097)

    September 18, 2019

    Aviv Sasson, a security researcher from the cloud division of Unit 42, has identified a critical vulnerability in a widespread cloud native registry called Harbor. The vulnerability allows attackers to take over Harbor registries by sending them a malicious request. The maintainers of Harbor released a patch that closes this critical security hole. Versions 1.7.6 and 1.8.3 include this fix. Unit 42 has ...

  • Intel CPUs Vulnerable to Sensitive Data Leakage in NetCAT Attack

    September 11, 2019

    Researchers have identified a new side-channel attack impacting all modern Intel server processors made since 2012. The vulnerability could allow bad actors to sniff out encrypted passwords as they are being typed into a secure shell session (SSH); but, luckily, such an attack would be difficult to launch. The attack, disclosed on Tuesday and dubbed NetCAT (short for Network Cache ...

  • Microsoft patches two zero-days in massive September 2019 Patch Tuesday

    September 10, 2019

    Microsoft has published today 80 security fixes across 15 products and services, as part of the company’s monthly batch of security updates, known as Patch Tuesday. Of the 80 vulnerabilities patched today, two are so-called zero-days — security flaws that had been exploited in the wild before Microsoft released fixes. The two zero-days are CVE-2019-1214 and CVE-2019-1215. Both are ...