Microsoft SharePoint Server Security Feature Bypass Vulnerability

ThreatsDay: 296K IoT Botnet, 100+ Water Systems Targeted, SharePoint RCE Chain + 27 New Stories

A fake login page. A fake security scan. A fake productivity app. Apparently, pretending to be useful is still one of the easier ways into a machine. The rest of the week gets stranger: botnets borrowing AI, command traffic hiding in public infrastructure, malicious tools waiting before showing their real behavior, exposed systems getting scanned, and exploit windows shrinking again. Different

Rapid7 Analysis: Microsoft SharePoint Remote Code Execution (CVE-2026-63520)

Patch Tuesday - August 2026

Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday, including 236 vulnerabilities in Windows. This is lower volume than last month’s record-breaking behemoth, but still one of the largest Patch Tuesday totals ever. There is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for one of the vulnerabilities published today, as well as public disclosure for two others, although the Notable CVEs section of the Security Update Guide omits one of these. As usual, browser vulns are not

Microsoft Patches 398 Flaws Including a Windows Driver Zero-Day Under Active Attack

Microsoft released its monthly security updates on Tuesday, and one of the flaws it closed is already being used in attacks. The bug sits in a core Windows kernel driver that handles network socket operations. An attacker with code already running on a machine can use it to escalate to SYSTEM. That patch goes out first. The flaw is tracked as CVE-2026-68820 (CVSS score: 7.0) and is the only

Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Security researchers found a way to enter Microsoft SharePoint servers as any user, including an administrator, with no valid account. A significant part of the work that found it was done through an AI agent. The flaw, tracked as CVE-2026-55040 (CVSS 9.1), affects SharePoint Server Subscription Edition, SharePoint Server 2019, and SharePoint Server 2016. Microsoft's

Microsoft komt vanavond met update voor RCE-lek in SharePoint

Microsoft komt vanavond met een beveiligingsupdate voor een kwetsbaarheid in SharePoint (CVE-2026-63520) waardoor remote code ...

Rapid7 Analysis: Microsoft SharePoint JWT Token Authentication Bypass (CVE-2026-55040)

OverviewOn July 14, 2026, Rapid7 and Microsoft disclosed CVE-2026-55040, an authentication bypass vulnerability affecting Microsoft SharePoint. Today we are publishing a technical analysis of the vulnerability along with an accompanying proof-of-concept (PoC) script.Figure 1: The Rapid7 Labs PoC for CVE-2026-55040.⠀A remote unauthenticated attacker can leverage CVE-2026-55040 to bypass authentication on a vulnerable SharePoint server, and perform operations as a SharePoint site user or administrator. The vulnerability is due to several issues in the JWT token validation pipeline.AnalysisThe fo

CVE-2026-63520: Microsoft SharePoint Remote Code Execution (FIXED)

OverviewRapid7 Labs conducted a zero-day research project against Microsoft SharePoint, resulting in the discovery of two new vulnerabilities that, when chained together, achieve unauthenticated remote code execution (RCE) against a vulnerable SharePoint server. Today, both Rapid7 and Microsoft are disclosing the second vulnerability in this chain, the RCE vulnerability CVE-2026-63520. The first vulnerability in the chain, CVE-2026-55040, was disclosed by Rapid7 and Microsoft last month.Our full disclosure timeline for the exploit chain can be seen below in Figure 1.Figure 1: The road to discl