This vulnerability (CVE-2026-41103) affects the Microsoft Confluence SAML SSO plugin version 1.0.0. It is caused by an incorrect implementation of the authentication algorithm (CWE-303), which enables an attacker to elevate privileges remotely without requiring prior authentication or user interaction. The CVSS v3.1 base score is 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality and integrity. Microsoft has published an official fix for this vulnerability, and the advisory is available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41103.

An attacker can exploit this vulnerability remotely over the network to elevate privileges without any authentication or user interaction. This leads to a complete compromise of confidentiality and integrity of the affected system, potentially allowing unauthorized access to sensitive information or administrative functions. Availability is not impacted.

An official fix is available from Microsoft. Users of the Microsoft Confluence SAML SSO plugin version 1.0.0 should apply the vendor-provided patch immediately to remediate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41103 for detailed update instructions.