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CVE-2026-34040 — Vulnerability in github.com/moby/moby — CVE Details

HIGH

Moby has AuthZ plugin bypass when provided oversized request bodies

Published March 27, 2026Updated September 8, 2026Source: osv

Summary

## Summary A security vulnerability has been detected that allows attackers to bypass [authorization plugins (AuthZ)](https://docs.docker.com/engine/extend/plugins_authorization/) under specific circumstances. The base likelihood of this being exploited is low. This is an incomplete fix for [CVE-2024-41110](https://github.com/moby/moby/security/advisories/GHSA-v23v-6jw2-98fq). ## Impact **If you don't use AuthZ plugins, you are not affected.** Using a specially-crafted API request, an attacker could make the Docker daemon forward the request to an authorization plugin without the body. The authorization plugin may allow a request which it would have otherwise denied if the body had been forwarded to it. Anyone who depends on authorization plugins that introspect the request body to make access control decisions is potentially impacted. ## Workarounds If unable to update immediately: - Avoid using AuthZ plugins that rely on request body inspection for security decisions. - Restrict access to the Docker API to trusted parties, following the principle of least privilege. ## Credits - 1seal / Oleh Konko ([@1seal](https://github.com/1seal)) - Cody (c@wormhole.guru) - Asim Viladi Oglu Manizada (@manizada) ## Resources - [CVE-2024-41110 / GHSA-v23v-6jw2-98fq](https://github.com/moby/moby/security/advisories/GHSA-v23v-6jw2-98fq)

Advisory Timeline

  • First published March 27, 2026 (199 days ago).
  • Last revised September 8, 2026 — 164 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

Go
Update github.com/moby/moby to 29.3.1 or later
go get github.com/moby/moby@v29.3.1
Go
Update github.com/moby/moby/v2 to 2.0.0-beta.8 or later
go get github.com/moby/moby/v2@v2.0.0-beta.8

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (2)

Affects 1 ecosystem: go (2).

PackageEcosystemAffectedFixed In
github.com/moby/moby
go
All versions29.3.1
github.com/moby/moby/v2
go
All versions2.0.0-beta.8

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 8.8 score means for each attack dimension.

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Frequently Asked Questions

What is CVE-2026-34040?
Moby has AuthZ plugin bypass when provided oversized request bodies This vulnerability has been assigned a severity rating of HIGH (CVSS score: 8.8/10).
How do I check if my project is affected by CVE-2026-34040?
CVE-2026-34040 affects github.com/moby/moby and github.com/moby/moby/v2. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2026-34040 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score
8.8

High exploitability or significant impact. Prioritize remediation within days.

Also Known As

GHSA-x744-4wpc-v9h2
GO-2026-4887

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