Is there a public PoC exploit available for CVE-2026-16763?

Yes, a public proof-of-concept exploit is available for CVE-2026-16763. Prioritise patching immediately. EPSS: 0.7%.

serverless-localstack CVE-2026-16763

Q: What is the CVSS score of CVE-2026-16763?

CVE-2026-16763 has a CVSS 4.0 base score of 1.9 (Low). CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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: 0.7%.

EUVD-2026-48434 LOW

OS Command Injection (CWE-78)

2026-07-23 VulDB

GHSA-64cc-4fc3-52m3

Command Injection Docker Serverless Localstack

1.9

CVSS 4.0 · Vendor: VulDB

Severity by source

Vendor (VulDB) PRIMARY

1.9 MEDIUM

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

vuln.today AI

5.3 MEDIUM

Local attack vector, low-privilege config write access required; limited impact across all three dimensions with no scope change.

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

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

Primary rating from Vendor (VulDB).

CVSS VectorVendor: VulDB

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

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Severity Changed

Jul 23, 2026 - 22:22 NVD

MEDIUM LOW

CVSS changed

Jul 23, 2026 - 22:22 NVD

4.8 (MEDIUM) 1.9 (LOW)

Analysis Generated

Jul 23, 2026 - 22:03 vuln.today

CVE Published

Jul 23, 2026 - 21:15 cve.org

MEDIUM 4.8

DescriptionCVE.org

A vulnerability was identified in localstack serverless-localstack up to 1.4.0. The affected element is an unknown function of the file src/index.js of the component Configuration Handler. The manipulation of the argument custom.localstack.docker.compose_file leads to os command injection. An attack has to be approached locally. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet.

AnalysisAI

OS command injection in localstack serverless-localstack up to version 1.4.0 allows a local low-privileged attacker to execute arbitrary operating system commands by manipulating the custom.localstack.docker.compose_file configuration argument processed by the Configuration Handler in src/index.js. A publicly available proof-of-concept exploit exists via GitHub issue #303, elevating practical risk beyond the moderate CVSS 4.0 base score of 4.8. No vendor patch has been released, as the project maintainer has not responded to the responsible disclosure reported through an issue report.

Technical ContextAI

serverless-localstack is a Serverless Framework plugin (CPE: cpe:2.3:a:localstack:serverless-localstack:*:*:*:*:*:*:*:*) that enables developers to emulate AWS cloud services locally using LocalStack and Docker. The vulnerability manifests in src/index.js within the Configuration Handler, which processes user-supplied plugin configuration values such as custom.localstack.docker.compose_file. CWE-78 (Improper Neutralization of Special Elements used in an OS Command - 'OS Command Injection') identifies the root cause: the docker.compose_file parameter is passed into a shell-executing function without sanitization or escaping, allowing embedded shell metacharacters or command sequences to be interpreted and executed by the operating system. Because this plugin interacts with Docker Compose, its configuration handling inherently invokes system-level processes, creating a natural injection surface.

RemediationAI

No vendor-released patch has been identified at time of analysis - the project maintainer has not responded to the responsible disclosure (GitHub issue #303). As an immediate compensating control, restrict write permissions on Serverless Framework configuration files (serverless.yml / serverless.json) to trusted developers only, preventing unauthorized modification of the custom.localstack.docker.compose_file parameter. Avoid supplying dynamic or externally sourced values for this configuration key; use only static, pre-validated file paths controlled by the project team. In CI/CD environments, isolate the build agent and enforce code review requirements on any changes to Serverless plugin configuration. Monitor the GitHub repository (https://github.com/localstack/serverless-localstack/) for an upstream fix and upgrade immediately once a patched release is published. If the plugin is not actively required, consider temporarily disabling or removing it from the Serverless Framework configuration as a trade-off against local AWS emulation capability.