Microsoft Exchange
CISA and NSA share tips on securing Microsoft Exchange servers
The Cybersecurity and Infrastructure Security Agency (CISA) and the National Security Agency (NSA) have released guidance to help IT administrators harden Microsoft Exchange servers on their networks against attacks. Recommended best practices include hardening user authentication and access, minimizing application attack surfaces, and ensuring strong network encryption. The agencies also advise network defenders to decommission […]
Microsoft: Exchange 2016 and 2019 reach end of support in 30 days
Microsoft has reminded administrators again that Exchange 2016 and Exchange 2019 will reach the end of extended support next month and has provided guidance for decommissioning outdated servers. According to the company’s product lifecycle website, Exchange 2016 reached mainstream end date in October 2020, while Exchange 2019’s mainstream support ended on January 9, 2024. Microsoft also reminded customers in January that […]
Over 29,000 Exchange servers unpatched against high-severity flaw
Over 29,000 Exchange servers exposed online remain unpatched against a high-severity vulnerability that can let attackers move laterally in Microsoft cloud environments, potentially leading to complete domain compromise. The security flaw (tracked as CVE-2025-53786) helps threat actors who gain administrative access to on-premises Exchange servers to escalate privileges within the organization’s connected cloud environment by […]
CISA orders fed agencies to patch new Exchange flaw by Monday
CISA has issued an emergency directive ordering all Federal Civilian Executive Branch (FCEB) agencies to mitigate a critical Microsoft Exchange hybrid vulnerability tracked as CVE-2025-53786 by Monday morning at 9:00 AM ET. Federal Civilian Executive Branch (FCEB) agencies are non-military agencies within the US executive branch, including the Department of Homeland Security, Department of the Treasury, Department of […]
Microsoft warns of high-severity flaw in hybrid Exchange deployments
Microsoft has warned customers to mitigate a high-severity vulnerability in Exchange Server hybrid deployments that could allow attackers to escalate their privileges in Exchange Online cloud environments without leaving any traces. Exchange hybrid configurations connect on-premises Exchange servers to Exchange Online (part of Microsoft 365), allowing for seamless integration of email and calendar features between […]
Microsoft: Exchange Server Subscription Edition now available
Microsoft has announced that the Exchange Server Subscription Edition (SE) is now available to all customers of its enterprise email service. As the company explained, the Exchange Server SE RTM build released this week can be installed as a cumulative update (CU) on servers running Exchange Server 2019 CU15 or CU14, and it can also […]
Washington Post’s email system hacked, journalists’ accounts compromised
Email accounts of several Washington Post journalists were compromised in a cyberattack believed to have been carried out by a foreign government. The incident was discovered on Thursday evening and the publication started an investigation. On Sunday, June 15, an internal memo was sent to employees, informing them of a “possible targeted unauthorized intrusion into their […]
US indicts Black Kingdom ransomware admin for Microsoft Exchange attacks
A 36-year-old Yemeni national, who is believed to be the developer and primary operator of ‘Black Kingdom’ ransomware, has been indicted by the United States for conducting 1,500 attacks on Microsoft Exchange servers. The suspect, Rami Khaled Ahmed, is accused of deploying the Black Kingdom malware on roughly 1,500 computers in the United States and abroad, […]
Microsoft: Exchange 2016 and 2019 reach end of support in six months
Microsoft warned that Exchange 2016 and Exchange 2019 will reach the end of support six months from now, on October 14. The Exchange Server Engineering Team also shared guidance for admins who need to decommission outdated servers until then, cautioning that Exchange 2016 and Exchange 2019 servers will be exposed to attacks since they’ll no […]
Microsoft: Outdated Exchange servers fail to auto-mitigate security bugs
Microsoft says outdated Exchange servers cannot receive new emergency mitigation definitions because an Office Configuration Service certificate type is being deprecated. Emergency mitigations (also known as EEMS mitigations) are delivered via the Exchange Emergency Mitigation Service(EEMS), introduced three years ago in September 2021. EEMS automatically applies interim mitigations for high-risk (and likely actively exploited) security flaws […]