What is the CVSS score of CVE-2026-34040?

CVE-2026-34040 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Docker Engine are affected by CVE-2026-34040?

A vulnerability in Docker Engine allows attackers to bypass access control policies enforced by authorization plugins, potentially enabling unauthorized API operations.. A patch is available.

Is there a public PoC exploit available for CVE-2026-34040?

Yes, a public proof-of-concept exploit is available for CVE-2026-34040. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-34040?

Within 24 hours: Identify all Docker Engine deployments using AuthZ plugins and assess exposure scope. Within 7 days: Obtain patch available per vendor advisory, test in non-production with your AuthZ plugin configuration, and develop rollout plan. Within 30 days: Deploy patch to all affected Docker Engine instances and validate that AuthZ plugin enforcement remains functional.

Docker Engine CVE-2026-34040

HIGH

Incorrect Authorization (CWE-863)

2026-03-27 https://github.com/moby/moby

GHSA-x744-4wpc-v9h2

Authentication Bypass Docker

7.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.8 HIGH

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

vuln.today AI

7.8 HIGH

Docker API is typically local (AV:L), low-priv API client suffices (PR:L), crafted request is trivial (AC:L), and AuthZ bypass yields full container/host control (C:H/I:H/A:H).

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

4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

SUSE

8.8 HIGH

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

Red Hat

8.4 MEDIUM

qualitative

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

Jun 16, 2026 - 14:59 vuln.today

v3 (cvss_changed)

Source Code Evidence Fetched

Jun 16, 2026 - 14:59 vuln.today

Analysis Updated

Jun 16, 2026 - 14:59 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jun 16, 2026 - 14:52 vuln.today

cvss_changed

CVSS changed

Jun 16, 2026 - 14:52 NVD

8.8 (HIGH) 7.8 (HIGH)

Analysis Generated

Mar 27, 2026 - 18:00 vuln.today

Patch released

Mar 27, 2026 - 18:00 nvd

Patch available

CVE Published

Mar 27, 2026 - 17:43 nvd

HIGH 8.8

DescriptionNVD

Summary

A security vulnerability has been detected that allows attackers to bypass authorization plugins (AuthZ) under specific circumstances. The base likelihood of this being exploited is low.

This is an incomplete fix for CVE-2024-41110.

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)
Cody (c@wormhole.guru)
Asim Viladi Oglu Manizada (@manizada)

Resources

CVE-2024-41110 / GHSA-v23v-6jw2-98fq

AnalysisAI

Authorization bypass in Docker Engine (moby) allows API clients to evade AuthZ plugin policy decisions by issuing requests whose body is not forwarded to the plugin, causing it to approve operations it would otherwise deny. This is an incomplete-fix regression of CVE-2024-41110 affecting deployments that rely on AuthZ plugins inspecting request bodies; publicly available exploit code exists but EPSS is 0.01% and SSVC exploitation status is 'none'.

Technical ContextAI

The flaw lives in moby/moby's pkg/authorization/authz.go, where the daemon decides whether to send the HTTP body alongside the AuthZRequest to the registered AuthZ plugin. The previous implementation gated body forwarding on r.ContentLength > 0 or chunked Transfer-Encoding and skipped the body when it exceeded a 1MB maxBodySize, allowing a crafted request to reach the plugin with no body and have its policy evaluated against headers/URL only. CWE-863 (Incorrect Authorization) applies: the plugin's policy depends on body content (e.g., container create payloads, mount sources, capabilities), so a stripped body defeats the access-control decision. The fix in commit e89edb1 replaces drainBody with a bufio.Reader.Peek that always streams the body to the plugin up to a new 4MiB limit and rejects oversize bodies outright. Affected CPEs are pkg:go/github.com/moby/moby, github.com/docker/docker, and the v2 module.

RemediationAI

Vendor-released patch: upgrade Docker Engine to docker-v29.3.1 or later (https://github.com/moby/moby/releases/tag/docker-v29.3.1); SUSE users can apply SUSE-SU-2026:1205 (https://www.suse.com/support/update/SUSE-SU-2026:1205/). If immediate upgrade is not possible, stop relying on AuthZ plugins that make decisions from request-body introspection and instead enforce policy on URL/method/headers only - accepting that this weakens body-aware controls such as restrictions on mount sources, capabilities or image fields. Tightly restrict access to the Docker API socket and TCP endpoint to trusted operators (the daemon socket is root-equivalent), and consider gating the API behind mTLS plus an external reverse proxy that performs body-aware policy checks before the request reaches dockerd. Review GHSA-v23v-6jw2-98fq and GHSA-x744-4wpc-v9h2 for vendor-specific guidance, and verify your AuthZ plugin vendor (e.g., Twistlock, OPA-based gatekeepers) has not issued additional mitigations.