CVE-2025-4318: AWS Amplify Studio UI Component Properties Has an Input Validation Issue

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 1.0%, percentile 62: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 62% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes @aws-amplify/codegen-ui-react (npm) <= 2.20.2, fixed in 2.20.3. Check your lockfile, including transitive dependencies.

What it is

The AWS Amplify Studio UI component property expressions in the aws-amplify/amplify-codegen-ui package lack input validation. This could potentially allow an authenticated user who has access to create or modify components to run arbitrary JavaScript code during the component rendering and build process.

From the GitHub advisory

Summary The AWS Amplify Studio amplify-codegen-ui is a package that generates front-end code from UI Builder entities (components, forms, views, and themes) primarily used in AWS Amplify Studio for component previews and in AWS Command Line Interface (AWS CLI) for generating component files in customers' local applications.

An issue exists in the Amplify Studio property binding process of the amplify-codegen-ui package that could potentially allow an authenticated user to run arbitrary JavaScript code during the component rendering and build process.

Impact When importing a component schema using the create-component command, Amplify Studio will import and generate the component on the users' behalf. The expression-binding function does not validate the component schema properties before converting them to expressions. As a result, an authenticated user who can create or modify components could run arbitrary JavaScript code during the component rendering and build process.

Impacted versions:

Patches This issue has been addressed partially in version 2.20.3 and additional fixes in 2.20.4. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.

Weakness type: CWE-95.

Product: @aws-amplify/codegen-ui-react (npm) · Assigned by: AMZN · Published: 2025-05-05

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: low (any account)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.98% probability of exploitation activity in the next 30 days; percentile 62.

Timeline

• 2025-05-05 — CVE record published by AMZN
• 2026-07-29 — CVE record last updated
• 2026-07-30 — GitHub-reviewed advisory GHSA-hf3j-86p7-mfw8 published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. aws.amazon.com aws.amazon.com
2. github.com github.com
3. github.com github.com

Vulnerability records

1. GitHub Advisory GHSA-hf3j-86p7-mfw8 github.com
2. CVE.org record CVE-2025-4318 cve.org
3. NVD entry CVE-2025-4318 nvd.nist.gov

Other references from the CVE record and advisory

1. blog.securelayer7.net blog.securelayer7.net
2. github.com github.com

Critical npm advisories · Today’s Security Digest