CVE-2026-79300

Case-sensitive Username Handling Enables Duplicate MFA Authenticators in SEP sesam

Published Sep 12, 2026 CVSS 3.1 · 3.5 Low EPSS < 1% KEV · Not listed
Description
SEP sesam before 5.2.0.24 mishandles User Authorization with MFA. If AD authentication is configured and MFA is enforced, an attacker can create a second OTP access capability. SEP sesam and Active Directory handle username capitalization differently, which may allow multiple SEP sesam user accounts to be created for the same Active Directory (AD) account. Active Directory treats usernames as case-insensitive, while SEP sesam distinguishes between different letter casing. As a result, the same AD user can be represented by multiple SEP sesam user accounts that differ only in username capitalization. When Active Directory authentication is configured and multi-factor authentication (MFA) is enforced, this behavior may allow an additional OTP Authenticator to be registered for the same AD account, reducing the effectiveness of MFA protection.

Remediation

Vendor Solution

The issue is fixed in latest release versions >= v5.2.0.24. It is strongly recommended to update, if AD authentication is in use.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Case-sensitive Username Handling Enables Duplicate MFA Authenticators in SEP sesam
Type Values Removed Values Added
Title MFA Bypass via Username Case Sensitivity in SEP sesam
Type Values Removed Values Added
Title MFA Bypass via Username Case Sensitivity in SEP sesam
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Multiple SEP sesam User Accounts via Case Sensitivity Allowing Extra MFA Factor
Type Values Removed Values Added
Title Multiple SEP sesam User Accounts via Case Sensitivity Allowing Extra MFA Factor
Type Values Removed Values Added
First Time appeared Sep
Sep sesam
Vendors & Products Sep
Sep sesam
Type Values Removed Values Added
Title SEP sesam MFA Bypass via Username Case Handling
Type Values Removed Values Added
Title SEP sesam MFA Bypass via Username Case Handling
Type Values Removed Values Added
Description SEP sesam before 5.2.0.24 mishandles User Authorization with MFA. If AD authentication is configured and MFA is enforced, an attacker can create a second OTP access capability. SEP sesam and Active Directory handle username capitalization differently, which may allow multiple SEP sesam user accounts to be created for the same Active Directory (AD) account. Active Directory treats usernames as case-insensitive, while SEP sesam distinguishes between different letter casing. As a result, the same AD user can be represented by multiple SEP sesam user accounts that differ only in username capitalization. When Active Directory authentication is configured and multi-factor authentication (MFA) is enforced, this behavior may allow an additional OTP Authenticator to be registered for the same AD account, reducing the effectiveness of MFA protection.
Weaknesses CWE-180
References
Metrics cvssV3_1

{'score': 3.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Sep 14, 2026, 4:22 PM
Reserved
Aug 25, 2026, 6:14 AM
Status
Deferred
Published
Sep 12, 2026, 11:17 PM
Modified
Sep 22, 2026, 8:00 PM