CVE-2026-53902: MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-

Routine

MEDIUM 6.5DOWNGRADE

CVE-2026-53902 is a medium-severity flaw (CVSS 6.5) affecting mycomplianceoffice. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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/group

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-266, CWE-863
Published	2026-07-01
Last modified	2026-10-25

Publisher (CNA): CERT.PL · Vendor: mycomplianceoffice

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-01 13:17 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

mycomplianceoffice mycomplianceoffice DOWNGRADE

Affected: 25.3.3.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 25.3.3.1

1. Check installed version

apt-cache policy mycomplianceoffice || rpm -q mycomplianceoffice || mycomplianceoffice --version

2. No fixed release: DOWNGRADE to a release before 25.3.3.1 (Debian / Ubuntu)

apt-cache madison mycomplianceoffice sudo apt install mycomplianceoffice=<VERSION_BEFORE_25.3.3.1> sudo apt-mark hold mycomplianceoffice

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mycomplianceoffice sudo dnf downgrade mycomplianceoffice-<VERSION_BEFORE_25.3.3.1> sudo dnf versionlock add mycomplianceoffice

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

CERT Polska: Vulnerabilities in MyComplianceOffice MCO software 2026-07-01

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53902?

mycomplianceoffice: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-53902 being exploited?

CVE-2026-53902 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53902 affect?

CVE-2026-53902 affects mycomplianceoffice. Severity is medium (CVSS 6.5). 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 privile

How urgent is CVE-2026-53902?

Priority 30/100. No elevated risk signals yet.

Related CVEs

CVE-2026-53906 HIGH 8.2 DOWNGRADE MCO is vulnerable to Path Disclosure and Path Traversal in file handling functionality related to data export
CVE-2026-53903 HIGH 8.1 DOWNGRADE MCO is vulnerable to an Insecure Direct Object Reference (IDOR) vulnerability in the /customer/servlet/mco/web
CVE-2026-53905 HIGH 7.1 DOWNGRADE MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/admin-view-hierarchy/ge
CVE-2026-53909 MEDIUM 6.5 DOWNGRADE MCO does not correctly validate types of uploaded files
CVE-2026-53907 MEDIUM 5.4 DOWNGRADE MCO is vulnerable to Stored Cross‑Site Scripting (XSS) via the application logo upload functionality

References

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