Critical CVSS 9.8 Actively exploited
CVE-2026-56164
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
What this means
- Exposure
- Exploitable remotely over the network, without authentication and with no action from the victim.
- Impact
- An attacker can read sensitive data, modify or destroy data and take the service offline.
- Weakness
- A sensitive function is reachable with no authentication at all.
- Likelihood
- Exploitation is not hypothetical: CISA has observed it in the wild.
What to doTop priority: CISA sets the remediation deadline at 17 July 2026. Start with the instances exposed to the internet.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.