July 21, 2025
Microsoft hit with SharePoint attack — one version still vulnerable
Patches have been issued for two versions of Microsoft's SharePoint software, while one version remains vulnerable.

A Microsoft store in New York, US, on Friday, Oct. 25, 2024. 

Jeenah Moon | Bloomberg | Getty Images

Microsoft has warned of “active attacks” targeting its SharePoint collaboration software, with security researchers noting that organizations worldwide stand to be affected by the breach.

The Cybersecurity and Infrastructure Security Agency said Sunday in a release that the vulnerability provides unauthenticated access to systems and full access to SharePoint content, enabling bad actors to execute code over the network.

CISA said that while the scope and impact of the attack continue to be assessed, the agency warned that it “poses a risk to organizations.”

Microsoft late Sunday issued fixes for customers to apply to two versions of the SharePoint software. Another 2016 version remains vulnerable and the company said it is working to develop a patch.

Researchers at Palo Alto Networks said the hack likely reached thousands of organizations globally.

“The exploits are real, in-the-wild and pose a serious threat,” they added.

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CNBC has reached out to Microsoft for additional comment and information.

In an alert on Saturday, Microsoft said the attack applies only to on-premises SharePoint servers, not those in the cloud like Microsoft 365. SharePoint software is commonly used by global businesses and organizations to store and collaborate on documents.

The vulnerability is especially concerning because it allows hackers to impersonate users or services even after the SharePoint server is patched, according to researchers at European cybersecurity firm Eye Security, which said it first identified the flaw.

SharePoint servers often connect to other Microsoft services such as Outlook and Teams, meaning such a breach can “quickly” lead to data theft and password harvesting, Eye Security researchers said.

Separately, Alaska Airlines briefly halted its ground operations for about three hours on Sunday due to an IT outage. It lifted the ground stop at roughly 2 a.m. EST, the carrier said in a statement.

It was unclear whether the outage was related to the SharePoint attack.