CVE-2026-41103 – Microsoft SSO Plugin for Jira & Confluence Elevation of Privilege Vulnerability

A critical elevation of privilege vulnerability exists in the Microsoft SSO Plugin for Jira and Confluence due to incorrect implementation of an authentication algorithm. An unauthenticated attacker could send a specially crafted SSO response during login and trick the system into accepting a forged identity, allowing unauthorized access without proper Microsoft Entra ID authentication.

CVSS Score: 9.1
SEVERITY: Critical
THREAT:
This vulnerability could allow an attacker to bypass authentication and access Jira or Confluence as a valid user. Depending on the compromised account’s permissions, the attacker could view sensitive information, modify content, and perform unauthorized actions.

EXPLOITS:
At the time of publication, Microsoft reports that the vulnerability was not publicly disclosed and was not exploited. Exploit Code Maturity is listed as Unproven, but exploitation is assessed as More Likely.

TECHNICAL SUMMARY:
CVE-2026-41103 is caused by incorrect implementation of an authentication algorithm in the Microsoft SSO Plugin for Jira and Confluence. An attacker can exploit the flaw by sending a specially crafted SSO response during the login process. This forged response can cause the system to accept an unauthorized identity, allowing the attacker to sign in without authenticating through Microsoft Entra ID. The vulnerability is network-based, low complexity, requires no privileges, and needs no user interaction.

EXPLOITABILITY:
Affected software is the Microsoft SSO Plugin for Jira and Confluence. Exploitation does not require authentication or user interaction. A successful attacker can gain access as a valid Jira or Confluence user, limited by that user’s authorization level.

BUSINESS IMPACT:
Compromise of Jira or Confluence can expose project plans, engineering data, internal documentation, security procedures, customer information, and operational workflows. Attackers may also modify content, tamper with tickets, or abuse trusted collaboration systems to support further attacks.

WORKAROUND:
No workaround is listed. Apply the official Microsoft fix for the Microsoft SSO Plugin for Jira and Confluence.

URGENCY:
This vulnerability requires urgent attention because it is Critical, has a CVSS score of 9.1, requires no privileges or user interaction, and exploitation is considered More Likely. Authentication bypass flaws in collaboration platforms can quickly become high-impact enterprise incidents.