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Openshift Data FoundationApplication · Redhat

CVE-2025-8766

MEDIUM · 6.4 CVSS v3.1 Published 2026-03-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A container privilege escalation flaw was found in certain Multi-Cloud Object Gateway Core images. This issue stems from the /etc/passwd file being created with group-writable permissions during build time. In certain conditions, an attacker who can execute commands within an affected container, even as a non-root user, can leverage their membership in the root group to modify the /etc/passwd file. This could allow the attacker to add a new user with any arbitrary UID, including UID 0, leading to full root privileges within the container

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In certain Multi-Cloud Object Gateway Core container images, the /etc/passwd file is created with group-writable permissions during the image build process. A non-root user who is a member of the root group can exploit this misconfiguration to modify /etc/passwd and create a new user with UID 0, effectively gaining root privileges within the container.

MitigationRebuild the affected container images ensuring /etc/passwd has restrictive permissions (e.g., 644 or 640) and is not group-writable. Alternatively, use a minimal /etc/passwd or ensure the base image is properly hardened.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Openshift Data FoundationApplication
Affected:= 4.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
High
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Multi-Cloud Object Gateway Core containers in use
    Check for containers or pods related to OpenShift Data Foundation version 4.0, specifically the Multi-Cloud Object Gateway Core component. Use 'oc get pods -A | grep mcg' or 'kubectl get pods -A | grep mcg' to list relevant containers.
    Affected if Multi-Cloud Object Gateway Core containers from OpenShift Data Foundation 4.0 are running in the environment
  2. Check /etc/passwd permissions inside the container
    Exec into the container and run 'ls -la /etc/passwd' to view permissions. The file should have permissions like 644 or 640 (owner read/write, group read-only, others read-only).
    Affected if The permissions show a 'w' in the group field (e.g., 646 or 664), indicating /etc/passwd is group-writable
  3. Verify group membership of non-root users
    Inside the container, run 'getent group root' to check who belongs to the root group (GID 0), and 'id <username>' for non-root users to check their supplementary groups.
    Affected if A non-root user has root (GID 0) as a supplementary group and /etc/passwd is group-writable

A user is affected if they are running Multi-Cloud Object Gateway Core containers from OpenShift Data Foundation 4.0 AND /etc/passwd has group-writable permissions AND a non-root user with root group membership exists in the container.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Rebuild the affected container images ensuring /etc/passwd has restrictive permissions (e.g., 644 or 640) and is not group-writable. Alternatively, use a minimal /etc/passwd or ensure the base image is properly hardened.

Fix this in Openshift Data Foundation Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-8766 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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