Incorrect Permission AssignmentWeakness · CWE-732

CVE-2026-12957

HIGH · 7.8 CVSS v3.1 Published 2026-06-23

Mitigation only

No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.

See remediation →

81/100

Remediation priority · High

No privileges

Official description

NVD · unedited

Improper trust boundary enforcement in Language Servers for AWS before version 1.65.0 on all supported platforms may allow a for arbitrary code execution. If a local user opens a maliciously crafted workspace, any commands within the project configuration files may be automatically executed. This issue requires the user to trust the workspace when prompted. To remediate this issue, users should upgrade to Language Servers for AWS version 1.65.0 or higher.

Technical summary

dbcve analysis · high confidence

Improper trust boundary enforcement in AWS Language Servers allows arbitrary code execution when a user opens a malicious workspace and chooses to trust it. The vulnerability stems from the application executing commands embedded in project configuration files without sufficient validation, enabling local privilege escalation.

MitigationUpgrade Language Servers for AWS to version 1.65.0 or higher to receive the trust boundary enforcement fix.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown

From the vector

Attack vector: Local
Complexity: Low
Privileges: None
User interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Locate AWS Language Server installation

Search for AWS Language Server binaries (amazon-lsp, aws-lsp, or language server executables from AWS Toolkit) using 'which amazon-lsp' or 'which aws-lsp' on Linux/macOS, or check common installation directories such as /usr/local/bin, ~/.local/bin, or on Windows check Program Files and user AppData folders; if installed as an IDE extension (AWS Toolkit for VS Code, JetBrains), check extension details for the language server component

Affected if AWS Language Server executable or extension is present on the system
Determine installed version

Run the located binary with --version flag (e.g., 'amazon-lsp --version' or 'aws-lsp --version'); for IDE extensions, right-click the AWS Toolkit extension in your IDE's extension manager and select 'Check for Updates' or view the extension details to see the included language server version

Affected if Returned version is below 1.65.0
Identify workspace trust usage

Review IDE activity logs or recent workspace history to determine if any workspaces from external or untrusted sources were opened and trusted; check IDE settings for workspace trust state in recent sessions - VS Code stores workspace trust state in .vscode folder metadata or recent workspaces file

Affected if User has opened and trusted workspaces from sources outside their direct control since installing the language server

Environment is affected if AWS Language Server version is below 1.65.0 AND the user has interacted with and trusted potentially malicious workspace directories containing crafted project configuration files

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Mitigation available No clean upgrade yet — mitigate in the meantime

Mitigation

Upgrade Language Servers for AWS to version 1.65.0 or higher to receive the trust boundary enforcement fix.

Recommended fix High confidence

Language Servers for AWS version 1.65.0

Check the current installed version of Language Servers for AWS
Download Language Servers for AWS version 1.65.0 or later from the official AWS source (aws.amazon.com or official GitHub releases)
Install or update to version 1.65.0 or higher following the standard installation process
Verify the installed version is 1.65.0 or higher to confirm the remediation

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory

Consultation4.0 h
Implementation2.0 h
Testing3.0 h
Review / QA2.0 h

11.0 hours of engineering $1,970

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Scan for this in your stack

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References

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12957 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2026-12957?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

Verified mitigations, workarounds, and config changes
Version or environment caveats, and links to real fixes
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsA vendor remedy is published

Severity 7.8 High

Exploit likelihood EPSS, next 30 days 0.2%

Remediation

A high-priority fix

Have this fixed 11 hrs · Moderate

Typical engagement from $1,970

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2026-12957 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

Check your environment

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

CVSS breakdown

Am I affected?

Remediation

References