CVE-2026-53902
Privilege Escalation in MCO
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.1
Privilege Escalation in MCO
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
- Record
CVE-2026-53902- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-266, CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-40948
7.1
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
- Record
EUVD-2026-40948- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-rgv6-j8h9-46fv
7.1
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile...
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
- Record
GHSA-rgv6-j8h9-46fv- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-266
- Updated
- 2026-11-02
NVD
7.1
MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
- Record
CVE-2026-53902- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-266, CWE-863
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53902 is a high vulnerability (CVSS 7.1) in Mycomplianceoffice Mco, published July 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. No source names a fixed version.