What is CVE-2026-12957?

CVE-2026-12957 is a high-severity incorrect permission assignment for critical resource vulnerability in @aws/lsp-codewhisperer (npm), affecting versions < 0.0.113. It is fixed in 0.0.113. A file, directory, or other resource is assigned permissions that allow broader access than intended.

Which versions of @aws/lsp-codewhisperer are affected by CVE-2026-12957?

@aws/lsp-codewhisperer (npm) versions < 0.0.113 is affected.

Is there a fix for CVE-2026-12957?

Yes. CVE-2026-12957 is fixed in 0.0.113. Upgrade to this version or later.

Is CVE-2026-12957 exploitable, and should I be worried?

Whether CVE-2026-12957 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-12957 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-12957?

Upgrade @aws/lsp-codewhisperer to 0.0.113 or later.

CVE-2026-12957 in @aws/lsp-codewhisperer

Q: Which versions of @aws/lsp-codewhisperer are affected by CVE-2026-12957?

@aws/lsp-codewhisperer (npm) versions < 0.0.113 is affected.

Q: Is there a fix for CVE-2026-12957?

Yes. CVE-2026-12957 is fixed in 0.0.113. Upgrade to this version or later.

Q: Is CVE-2026-12957 exploitable, and should I be worried?

Whether CVE-2026-12957 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-12957 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-12957?

Upgrade @aws/lsp-codewhisperer to 0.0.113 or later.

Summary

Language Servers for AWS Vulnerable to Arbitrary Code Execution

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.

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 or directly via email to [email protected]. 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.

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.

A file, directory, or other resource is assigned permissions that allow broader access than intended. Typical impact: unauthorized read, modification, or execution of the resource.

Affected versions

@aws/lsp-codewhisperer (< 0.0.113)

Security releases

@aws/lsp-codewhisperer → 0.0.113 (npm)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

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.

Frequently Asked Questions

What is CVE-2026-12957? CVE-2026-12957 is a high-severity incorrect permission assignment for critical resource vulnerability in @aws/lsp-codewhisperer (npm), affecting versions < 0.0.113. It is fixed in 0.0.113. A file, directory, or other resource is assigned permissions that allow broader access than intended.
Which versions of @aws/lsp-codewhisperer are affected by CVE-2026-12957? @aws/lsp-codewhisperer (npm) versions < 0.0.113 is affected.
Is there a fix for CVE-2026-12957? Yes. CVE-2026-12957 is fixed in 0.0.113. Upgrade to this version or later.
Is CVE-2026-12957 exploitable, and should I be worried? Whether CVE-2026-12957 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-12957 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-12957? Upgrade @aws/lsp-codewhisperer to 0.0.113 or later.

Other vulnerabilities in @aws/lsp-codewhisperer

CVE-IDSeverityPackage summary

CVE-2026-12958High@aws/lsp-codewhisperer: Language Servers for AWS vulnerable to arbitrary file write