A faulty URL filtering rule update in Microsoft Exchange Online triggered a widespread false-positive storm beginning February 9, 2026, causing legitimate email messages to be incorrectly flagged as phishing and quarantined, disrupting email workflows for organizations globally. Microsoft tracked the incident under reference EX1227432. The issue was officially resolved on February 13, 2026, after a […] The post Microsoft 365 Exchange URL Filtering Update Quarantines Legitimate Emails as Phishing appeared first on Cyber Security News.