Vulnerability-Lookup

GHSA-XHCR-J4J9-3GH7

Vulnerability from github – Published: 2026-09-24 19:13 – Updated: 2026-09-24 19:13

Summary

Language Servers for AWS Vulnerable to Arbitrary Code Execution

Details

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 or directly via email to 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.

Severity

8.5 (High)


                  
                    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

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@aws/lsp-codewhisperer"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.113"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-12957"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-732"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-24T19:13:53Z",
    "nvd_published_at": "2026-06-23T17:16:40Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nLanguage Servers for AWS (the aws/language-servers project) provide the underlying language-server runtime that powers Amazon Q Developer\u0027s 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\u0027s project-level configuration files may be executed automatically, resulting in arbitrary code execution on the\nuser\u0027s 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 \u003c1.65.0.\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.",
  "id": "GHSA-xhcr-j4j9-3gh7",
  "modified": "2026-09-24T19:13:53Z",
  "published": "2026-09-24T19:13:53Z",
  "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Language Servers for AWS Vulnerable to Arbitrary Code Execution"
}

CVE-2026-12957 (GCVE-0-2026-12957)

Vulnerability from cvelistv5 – Published: 2026-06-23 16:02 – Updated: 2026-06-23 17:50

Title

Arbitrary Code Execution in Language Servers for AWS

Summary

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.

Severity

8.5 (High)


                        
                          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

7.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-23 17:48 UTC

CWE

CWE-732 - Incorrect Permission Assignment for Critical Resource

Assigner

AMZN mitre root Scorecard

References

2 references

URL	Tags
https://aws.amazon.com/security/security-bulletin…	vendor-advisory
https://github.com/aws/language-servers/security/…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
Amazon Web Services	Language Servers for AWS	Affected: 0 , < 1.65.0 (semver)

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

GHSA-XHCR-J4J9-3GH7

Summary

Impact

Patches

Workarounds

References

Acknowledgement

CVE-2026-12957 (GCVE-0-2026-12957)

Tags

Sightings

Nomenclature

Related by attack behaviour