SharePoint Server 2019

Related CVEsby mentions

• CVE-2026-505229.885%
  Unauthenticated Deserialization RCE in Microsoft SharePoint Server
  CVE-2026-50522 is a deserialization of untrusted data flaw (CWE-502) in Microsoft SharePoint Server that allows an unauthenticated attacker to send maliciously crafted serialized data over the network and execute code on the server, reflected in its 9.8 critical CVSS score with no privileges or user interaction required. Successful exploitation yields full remote code execution with high impact on confidentiality, integrity, and availability, giving attackers a foothold for follow-on actions such as data theft, lateral movement, or ransomware. Any organization running on-premises SharePoint Server is in scope, particularly deployments reachable from untrusted networks; the required action notes stakeholders must evaluate each asset's internet exposure under CISA BOD 26-04. The flaw is under active exploitation: CISA added it to the Known Exploited Vulnerabilities catalog on 2026-07-22 and security news headlines describe it as a critical RCE exploited in the wild, with some reports referencing exploitation after a public proof-of-concept release and an authentication bypass. The structured record lists no public PoC as confirmed, but an EPSS of 84.6% (100th percentile) underscores a very high near-term exploitation likelihood.
  · Microsoft SharePoint Server (on-premises) KEVmass
• CVE-2026-550409.151%
  Authentication Bypass in Microsoft SharePoint Server
  Microsoft SharePoint Server is affected by a weak authentication vulnerability (CWE-1390) that allows an unauthorized attacker to bypass a security feature over a network. Per the CVSS vector, exploitation requires no privileges and no user interaction with low attack complexity, so any unauthenticated attacker with network access to a vulnerable server can trigger it remotely. Impact to confidentiality and integrity is rated high (CVSS 9.1, critical), meaning the bypass effectively grants the attacker access that authentication should have prevented, with no direct availability impact. All organizations running on-premises Microsoft SharePoint Server are potentially affected; the source data does not specify affected version ranges or fixed builds, so defenders should consult Microsoft's advisory for those details. The flaw is under active exploitation: a public proof-of-concept is available on GitHub, attackers began exploiting it after the PoC went public, and CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-18 (EPSS ~40%, 99th percentile; ransomware association unknown).
  · Microsoft SharePoint Server KEV PoC ×2mass
• CVE-2026-635208.13%
  Unauthenticated RCE in Microsoft SharePoint Server
  CVE-2026-63520 is an improper input validation flaw (CWE-20) in Microsoft Office SharePoint, affecting on-premises SharePoint Server deployments. A remote, unauthenticated attacker can trigger the flaw by sending improperly validated input to the SharePoint service over the network; the high attack complexity (AC:H) indicates exploitation depends on specific conditions, but no privileges or user interaction are required. Successful exploitation results in arbitrary code execution on the server, with high impact to confidentiality, integrity, and availability — effectively full compromise of the SharePoint host. Organizations running self-hosted SharePoint Server are in scope; SharePoint Online/Microsoft 365 is not listed in the affected products. The issue is patched as of Microsoft's Patch Tuesday (headlines mark it FIXED), with Rapid7 analysis and a researcher-disclosed exploit chain available, but there is no public PoC, no CISA KEV listing, and no confirmed in-the-wild exploitation; EPSS puts exploitation probability at 2.9% (86th percentile).
  · Microsoft SharePoint Server (Office SharePoint, on-premises)mass

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