Which versions of Amazon ECS Agent are affected by EUVD-2026-26412?

Amazon ECS Agent versions prior to 1.103.0 contain a command injection vulnerability in Windows FSx volume mounting that allows authenticated users with task definition permissions to execute…. A patch is available.

Is there a public PoC exploit available for EUVD-2026-26412?

Yes, a public proof-of-concept exploit is available for EUVD-2026-26412. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate EUVD-2026-26412?

Within 24 hours: inventory all Windows ECS clusters and identify agents running versions below 1.103.0 using AWS Systems Manager or ECS API queries. Within 7 days: update ECS Agent to version 1.103.0 or later across all affected Windows instances; apply updates during maintenance windows to avoid container service interruption. Within 30 days: audit IAM policies limiting task definition registration and credential store access to principle of least privilege; enable CloudTrail monitoring on ECS task definition changes.

Amazon ECS Agent EUVD-2026-26412

Q: What is the CVSS score of EUVD-2026-26412?

EUVD-2026-26412 has a CVSS 4.0 base score of 7.5 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

| CVE-2026-7461 HIGH

OS Command Injection (CWE-78)

2026-04-30 AMZN

Microsoft Command Injection

7.5

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Re-analysis Queued

Apr 30, 2026 - 19:22 vuln.today

cvss_changed

CVSS changed

Apr 30, 2026 - 19:22 NVD

7.2 (HIGH) 7.5 (HIGH)

Source Code Evidence Fetched

Apr 30, 2026 - 19:16 vuln.today

Analysis Generated

Apr 30, 2026 - 19:16 vuln.today

EUVD ID Assigned

Apr 30, 2026 - 19:00 euvd

EUVD-2026-26412

Analysis Generated

Apr 30, 2026 - 19:00 vuln.today

Patch released

Apr 30, 2026 - 19:00 nvd

Patch available

CVE Published

Apr 30, 2026 - 18:35 nvd

HIGH 7.5

DescriptionCVE.org

Improper neutralization of inputs used in an OS command in the FSx Windows File Server volume mounting component in Amazon ECS Agent on Windows before version 1.103.0 might allow a remote authenticated threat actor to execute shell commands with SYSTEM privileges on the underlying host via a specially crafted username field in an ECS task definition. This issue requires permissions to register ECS task definitions or write to the Secrets Manager or SSM Parameter Store credentials used by the FSx volume configuration.

To remediate this issue, users should upgrade to version 1.103.0.

AnalysisAI

Command injection in Amazon ECS Agent on Windows allows authenticated attackers with task definition permissions to execute arbitrary shell commands with SYSTEM privileges on the underlying host. The vulnerability exists in the FSx Windows File Server volume mounting component (versions prior to 1.103.0), where username field input is not properly sanitized before being passed to OS commands. This affects AWS customers running Windows-based ECS container workloads with FSx volumes - exploitation requires IAM permissions to register ECS task definitions or write to credential stores (Secrets Manager/SSM Parameter Store) used by FSx configurations. Vendor-released patch: version 1.103.0. EPSS and KEV data not provided; no public exploit identified at time of analysis.

Technical ContextAI

This is a CWE-78 (OS Command Injection) vulnerability in the Amazon ECS Agent's Windows implementation, specifically the FSx for Windows File Server volume mounting subsystem. The affected component (cpe:2.3:a:aws:amazon_ecs_agent:*:*:*:*:*:*:*:*) processes ECS task definitions containing FSx volume configurations with credentials stored in AWS Secrets Manager or SSM Parameter Store. According to GitHub PR #4934 in the fix release, the vulnerability stems from unsafe direct interpolation of the username field into OS commands during the mount operation. Instead of sanitizing inputs before shell execution, the vulnerable code passes user-controlled task definition parameters directly to Windows command-line utilities with SYSTEM privileges. The patch remediation (v1.103.0) implements environment variable-based input handling to prevent command injection, alongside a Golang version bump to 1.25.9 for additional security improvements.

RemediationAI

Upgrade Amazon ECS Agent to version 1.103.0 or later per AWS Security Bulletin 2026-024-AWS (https://aws.amazon.com/security/security-bulletins/2026-024-aws/). The patch implements environment variable-based input handling for FSx volume mounting (GitHub PR #4934) to prevent command injection. For environments unable to immediately upgrade, implement compensating controls: (1) Audit and restrict IAM permissions for ecs:RegisterTaskDefinition, secretsmanager:PutSecretValue, and ssm:PutParameter actions to trusted principals only via least-privilege policies - note this may impact developer workflows requiring task definition updates; (2) Enable AWS CloudTrail logging for RegisterTaskDefinition API calls and configure CloudWatch alarms for unusual username patterns in task definition parameters (regex monitoring for shell metacharacters in FSx credential fields); (3) Consider temporarily disabling FSx for Windows File Server volume support on ECS clusters running vulnerable agent versions if the feature is not operationally required - this breaks existing FSx-dependent tasks. The patch also upgrades Golang to 1.25.9 for additional security improvements. Verify upgrade success by checking ECS agent version via AWS Systems Manager or container instance metadata.