SB2026031078 - Information disclosure in Microsoft Authenticator
Published: March 10, 2026
Security Bulletin ID
SB2026031078
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper Authorization in Handler for Custom URL Scheme (CVE-ID: CVE-2026-26123)
CWE-ID: CWE-939 - Improper Authorization in Handler for Custom URL Scheme
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to improper authorization in handler for custom URL scheme in Microsoft Authenticator. A remote attacker can gain access to sensitive information if the user selects a malicious application as the handler for the sign‑in deep link.
Remediation
Install update from vendor's website.