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Moby has an Off-by-one error in its plugin privilege validation

Moderate severity GitHub Reviewed Published Mar 25, 2026 in moby/moby • Updated Mar 31, 2026

Package

gomod github.com/docker/docker (Go)

Affected versions

< 29.3.1

Patched versions

None
gomod github.com/moby/moby (Go)
< 29.3.1
None
gomod github.com/moby/moby/v2 (Go)
< 2.0.0-beta.8
2.0.0-beta.8

Description

Summary

A security vulnerability has been detected that allows plugins privilege validation to be bypassed during docker plugin install. Due to an error in the daemon's privilege comparison logic, the daemon may incorrectly accept a privilege set that differs from the one approved by the user.

Plugins that request exactly one privilege are also affected, because no comparison is performed at all.

Impact

If plugins are not in use, there is no impact.

When a plugin is installed, the daemon computes the privileges required by the plugin's configuration and compares them with the privileges approved during installation. A malicious plugin can exploit this bug so that the daemon accepts privileges that differ from what was intended to be approved.

Anyone who depends on the plugin installation approval flow as a meaningful security boundary is potentially impacted.

Depending on the privilege set involved, this may include highly sensitive plugin permissions such as broad device access.

For consideration: exploitation still requires a plugin to be installed from a malicious source, and Docker plugins are relatively uncommon. Docker Desktop also does not support plugins.

Workarounds

If unable to update immediately:

  • Do not install plugins from untrusted sources
  • Carefully review all privileges requested during docker plugin install
  • Restrict access to the Docker daemon to trusted parties, following the principle of least privilege
  • Avoid relying on plugin privilege approval as the only control boundary for sensitive environments

Credits

References

@vvoland vvoland published to moby/moby Mar 25, 2026
Published to the GitHub Advisory Database Mar 27, 2026
Reviewed Mar 27, 2026
Published by the National Vulnerability Database Mar 31, 2026
Last updated Mar 31, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(5th percentile)

Weaknesses

Off-by-one Error

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. Learn more on MITRE.

CVE ID

CVE-2026-33997

GHSA ID

GHSA-pxq6-2prw-chj9

Source code

Credits

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