Ravie LakshmananJul 21, 2026Vulnerability / Web Security
A third SharePoint Server flaw patched by Microsoft as part of its Patch Tuesday update for July 2026 has come under active exploitation, per watchTowr.
The vulnerability in question is CVE-2026-50522 (CVSS score: 9.8), a critical deserialization of untrusted data in Microsoft Office SharePoint that could allow an unauthorized attacker to execute code over a network. Microsoft credited DEVCORE researcher "splitline" with discovering and reporting the flaw.
"In a network-based attack, an attacker authenticated as at least a Site Owner, could write arbitrary code to inject and execute code remotely on the SharePoint Server," Redmond said in an advisory released last week.
"The attack vector is Network (AV:N) because this vulnerability is remotely exploitable and can be exploited from the internet. The attack complexity is Low (AC:L) because an attacker does not require significant prior knowledge of the system and can achieve repeatable success with the payload against the vulnerable component."
