CVE-2026-12957: @aws/lsp codewhisperer Language Servers For AWS Vulnerable Vulnerability

Q: What is CVE-2026-12957?

CVE-2026-12957 is a security vulnerability in @aws/lsp codewhisperer involving Language Servers for AWS Vulnerable to Arbitrary Code Execution under CWE-732: Incorrect Permission Assignment for Critical Resource.

Q: Which @aws/lsp codewhisperer versions are affected?

Affected versions include releases prior to 0.0.113 across affected packages: @aws/lsp-codewhisperer.

Q: What version fixes CVE-2026-12957?

Upgrading to 0.0.113 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is @aws/lsp-codewhisperer affected?

Yes, @aws/lsp-codewhisperer is affected in releases prior to 0.0.113. Upgrade your dependency to 0.0.113 or later.

Q: What CWE is associated with CVE-2026-12957?

CVE-2026-12957 is classified under CWE-732: Incorrect Permission Assignment for Critical Resource (The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.).

Q: How can I check npm dependencies for CVE-2026-12957?

Run the dependency tree command: 'npm ls @aws/lsp-codewhisperer'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

HIGH

Advisory Identifier: GHSA-xhcr-j4j9-3gh7

CWE-732

Published 2026-09-24

Advisory Summary

CVE-2026-12957 is a HIGH language servers for aws vulnerable vulnerability (CWE-732: Incorrect Permission Assignment for Critical Resource) affecting @aws/lsp codewhisperer libraries in the npm ecosystem. The issue involves language servers for aws vulnerable to arbitrary code execution. Remediation is available by upgrading affected packages to version 0.0.113.

CVE-2026-12957 at a Glance

CVE Identifier CVE-2026-12957

GHSA Identifier GHSA-xhcr-j4j9-3gh7

Severity HIGH

CVSS v3.1 Base Score N/A

CWE Classification CWE-732: Incorrect Permission Assignment for Critical Resource

Affected Product @aws/lsp codewhisperer

Package Ecosystem npm

Published Date 2026-09-24

Last Updated 2026-09-24

How to Fix CVE-2026-12957

To remediate this vulnerability, upgrade all affected @aws/lsp codewhisperer dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@aws/lsp-codewhisperer fixed: 0.0.113

npm install @aws/lsp-codewhisperer@0.0.113

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls @aws/lsp-codewhisperer

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-12957, inspect your project dependencies using npm:

npm ls @aws/lsp-codewhisperer

Analyze the terminal output to locate any version of @aws/lsp codewhisperer in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.113), your application is affected.

Note: The npm ls @aws/lsp-codewhisperer command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-732: Incorrect Permission Assignment for Critical Resource, where the product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. In @aws/lsp codewhisperer, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary Language Servers for AWS (the aws/language-servers project) provide the underlying language-server runtime that powers Amazon Q Developer's AI coding assistance across its IDE plugins (Visual Studio Code, JetBrains, Eclipse, and Visual Studio). Improper trust boundary enforcement in Language Servers for AWS may allow for arbitrary code execution. If a local user opens a maliciously crafted workspace, any commands within the project configuration files may be automatically executed. ### Impact When a local user opens a maliciously crafted workspace and trusts it when prompted, commands defined in the workspace's project-level configuration files may be executed automatically, resulting in arbitrary code execution on the user's host. This issue is triggered when a user opens a workspace, trusts it, and the agent subsequently executes commands defined in the project-level configuration files. Impacted versions: Language Servers for AWS version <1.65.0. ### Patches This issue has been addressed in Language Servers for AWS version 1.65.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. ### Workarounds No workarounds are available. ### References If you have any questions or comments about this advisory, AWS Security asks that you contact them via their [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue. ### Acknowledgement AWS Security would like to thank Wiz and Maor Dokhanian for collaborating on this issue through the coordinated vulnerability disclosure process.

CVE-2026-12957 Affected @aws/lsp codewhisperer Versions

1 component(s)

Fixed Versions:

0.0.113

Product / Package	Ecosystem	Affected Versions	Fixed Version
@aws/lsp-codewhisperer npm/@aws/lsp-codewhisperer	npm	< 0.0.113	0.0.113

References

GitHub Advisory / Wiki ADVISORY

https://github.com/aws/language-servers/security/advisories/GHSA-xhcr-j4j9-3gh7

NVD — CVE-2026-12957 NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-12957

@aws/lsp codewhisperer Source Repository REPOSITORY

https://github.com/Amazon-Q-Developer/language-servers/pull/2708

@aws/lsp codewhisperer Source Repository REPOSITORY

https://github.com/Amazon-Q-Developer/language-servers/pull/2711

Security Fix Commit FIX COMMIT

https://github.com/Amazon-Q-Developer/language-servers/commit/7b8595a4e638562f79d5f71dcf22b0c700490458

Security Fix Commit FIX COMMIT

https://github.com/Amazon-Q-Developer/language-servers/commit/f5aa1a3b25aa38bfe8dd0e830b5839e1cea1d410

@aws/lsp codewhisperer Security Information SECURITY

https://aws.amazon.com/security/security-bulletins/2026-047-aws

@aws/lsp codewhisperer Release RELEASE

https://github.com/Amazon-Q-Developer/language-servers/releases/tag/agentic-rc-1.65.0

@aws/lsp codewhisperer Source Repository REPOSITORY

https://github.com/aws/language-servers

Frequently Asked Questions

What is CVE-2026-12957?

CVE-2026-12957 is a security vulnerability in @aws/lsp codewhisperer involving Language Servers for AWS Vulnerable to Arbitrary Code Execution under CWE-732: Incorrect Permission Assignment for Critical Resource.

Which @aws/lsp codewhisperer versions are affected?

Affected versions include releases prior to 0.0.113 across affected packages: @aws/lsp-codewhisperer.

What version fixes CVE-2026-12957?

Upgrading to 0.0.113 (or the latest patched release for your respective branch) resolves the vulnerability.

Is @aws/lsp-codewhisperer affected?

Yes, @aws/lsp-codewhisperer is affected in releases prior to 0.0.113. Upgrade your dependency to 0.0.113 or later.

What CWE is associated with CVE-2026-12957?

CVE-2026-12957 is classified under CWE-732: Incorrect Permission Assignment for Critical Resource (The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.).

How can I check npm dependencies for CVE-2026-12957?

Run the dependency tree command: 'npm ls @aws/lsp-codewhisperer'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

Machine-readable OSV JSON OSV v1.5 Schema

Normalized schema output

View Raw JSON

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xhcr-j4j9-3gh7",
  "modified" : "2026-09-24T19:13:53Z",
  "published" : "2026-09-24T19:13:53Z",
  "aliases" : [ "CVE-2026-12957" ],
  "summary" : "Language Servers for AWS Vulnerable to Arbitrary Code Execution",
  "details" : "### Summary\nLanguage Servers for AWS (the aws/language-servers project) provide the underlying language-server runtime that powers Amazon Q Developer's AI coding assistance across its IDE plugins (Visual Studio Code, JetBrains, Eclipse, and\nVisual Studio).\n\nImproper trust boundary enforcement in Language Servers for AWS may allow for arbitrary code execution. If a local user opens a maliciously crafted workspace, any commands within the project configuration files may be automatically\nexecuted.\n\n### Impact\n\nWhen a local user opens a maliciously crafted workspace and trusts it when prompted, commands defined in the workspace's project-level configuration files may be executed automatically, resulting in arbitrary code execution on the\nuser's host.\n\nThis issue is triggered when a user opens a workspace, trusts it, and the agent subsequently executes commands defined in the project-level configuration files.\n\n\nImpacted versions: Language Servers for AWS version <1.65.0.\n\n### Patches\nThis issue has been addressed in Language Servers for AWS version 1.65.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. \n\n### Workarounds\nNo workarounds are available.\n\n### References\nIf you have any questions or comments about this advisory, AWS Security asks that you contact them via their [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.\n\n### Acknowledgement \n\nAWS Security would like to thank Wiz and Maor Dokhanian for collaborating on this issue through the coordinated vulnerability disclosure process.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@aws/lsp-codewhisperer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.113"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/aws/language-servers/security/advisories/GHSA-xhcr-j4j9-3gh7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-12957"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Amazon-Q-Developer/language-servers/pull/2708"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Amazon-Q-Developer/language-servers/pull/2711"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Amazon-Q-Developer/language-servers/commit/7b8595a4e638562f79d5f71dcf22b0c700490458"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Amazon-Q-Developer/language-servers/commit/f5aa1a3b25aa38bfe8dd0e830b5839e1cea1d410"
  }, {
    "type" : "WEB",
    "url" : "https://aws.amazon.com/security/security-bulletins/2026-047-aws"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Amazon-Q-Developer/language-servers/releases/tag/agentic-rc-1.65.0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/aws/language-servers"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-732" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-24T19:13:53Z",
    "nvd_published_at" : "2026-06-23T17:16:40Z"
  }
}

CVSS V4

N/A HIGH

Attack Vector N/A

Attack Complexity N/A

Privileges Required N/A

User Interaction N/A

Scope N/A

Confidentiality N/A

Integrity N/A

Availability N/A

Vector String

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

Advisory Metadata

Source ID: GHSA-xhcr-j4j9-3gh7
Schema Version: 1.4.0
Published: 2026-09-24 19:13
Last Modified: 2026-09-24 19:13
Database Record File: advisories/github-reviewed/2026/09/GHSA-xhcr-j4j9-3gh7/GHSA-xhcr-j4j9-3gh7.json