CVE-2026-78515

Office productivity vulnerabilities (Word, Excel, Acrobat) are primary vectors for phishing-delivered malware — one opened file can compromise the entire company.

Malicious document arrives via email. Macro or exploit executes silently. Attacker gains persistent access to the employee's machine and credentials.

Apply the patch from this month's Microsoft Patch Tuesday via Windows Update. For managed environments, push via WSUS or Microsoft Endpoint Manager. Prioritise servers and domain controllers over workstations.

The affected service is reachable over the network. Verify that it is not exposed to the internet unnecessarily. Apply network segmentation to limit blast radius if exploited.

Exploitation requires user interaction (e.g., opening a file, clicking a link). While patching is the definitive fix, remind users not to open unexpected attachments or links. This type of vulnerability is commonly chained with phishing campaigns targeting SMBs.