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:

  • CISA Releases Nine Industrial Control Systems Advisories

    June 29, 2023

    CISA released nine Industrial Control Systems (ICS) advisories on June 29, 2023. These advisories provide timely information about current security issues, vulnerabilities, and exploits surrounding ICS. ICSA-23-180-01 Delta Electronics InfraSuite Device Master ICSA-23-180-02 Schneider Electric EcoStruxure ICSA-23-180-03 Ovarro TBox RTUs Read more… Source: U.S. Cybersecurity and Infrastructure Security Agency  

  • CISA Adds Five Known Exploited Vulnerabilities to Catalog

    June 23, 2023

    CISA has added five new vulnerabilities to its Known Exploited Vulnerabilities Catalog, based on evidence of active exploitation. CVE-2023-32434 Apple Multiple Products Integer Overflow Vulnerability CVE-2023-32435 Apple iOS and iPadOS WebKit Memory Corruption Vulnerability Read more… Source: U.S. Cybersecurity and Infrastructure Security Agency  

  • Apple Releases Security Updates for Multiple Products

    June 22, 2023

    Apple has released security updates to address vulnerabilities in multiple products. An attacker could exploit some of these vulnerabilities to take control of an affected device. CISA encourages users and administrators to review the following advisories and apply the necessary updates. watchOS 8.8.1 macOS Big Sur 11.7.8 macOS Monterey 12.6.7 Read more… Source: U.S. Cybersecurity and Infrastructure Security Agency  

  • CISA Releases Two Industrial Control Systems Advisories

    June 20, 2023

    CISA released two Industrial Control Systems (ICS) advisories on June 20, 2023. These advisories provide timely information about current security issues, vulnerabilities, and exploits surrounding ICS. ICSA-23-171-01 Enphase Envoy Read more… Source: U.S. Cybersecurity and Infrastructure Security Agency  

  • Whitehall wide open to cyber-attack, warn campaigners

    June 18, 2023

    Government departments responsible for running health and social care, and for collecting taxes, are using outdated software that leaves them wide open to cyber-attacks, according to a disturbing new investigation. The use of “legacy” servers and databases has been uncovered through freedom of information (FoI) requests from the low-tax pressure group the TaxPayers’ Alliance. It has ...

  • Barracuda ESG Zero-Day Vulnerability (CVE-2023-2868) Exploited Globally by Aggressive and Skilled Actor, Suspected Links to China

    June 15, 2023

    Starting as early as October 10, 2022, UNC4841 sent emails to victim organizations that contained malicious file attachments designed to exploit CVE-2023-2868 to gain initial access to vulnerable Barracuda ESG appliances. Over the course of their campaign, UNC4841 has primarily relied upon three principal code families to establish and maintain a presence on an ESG appliance, ...