GHSA-WCX4-WPFV-MC5C
Vulnerability from github – Published: 2026-08-07 18:15 – Updated: 2026-08-07 18:15Summary
jsii-diff is a command line tool to compare the API differences between two jsii assemblies, and report errors if there are backwards-incompatible changes to the API. An issue exists where specially formatted command line arguments can be used to execute shell commands via this tool.
Impact
jsii-diff supports downloading packages to compare directly from NPM, so that you can compare a proposed candidate version of your jsii package with an already-published version, by passing an argument that looks like npm:<package-specifier>. For example:
jsii-diff npm:my-package@latest .
By injecting a ; into the package-specifier part of that command, jsii-diff can be tricked into running shell commands. For example:
jsii-diff "npm:lodash; touch /tmp/123" .
This allows anyone that can control the command-line arguments to jsii-diff to run arbitrary commands with the same permissions as the jsii-diff command itself.
Patches
This issue has been addressed in jsii-diff version 1.131.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
If you are unable to update, make sure only trusted actors can control the arguments passed to jsii-diff.
References
If you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "jsii-diff"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.131.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-15895"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-07T18:15:47Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\njsii-diff is a command line tool to compare the API differences between two jsii assemblies, and report errors if there are backwards-incompatible changes to the API. An issue exists where specially formatted command line arguments can be used to execute shell commands via this tool.\n\n## Impact\njsii-diff supports downloading packages to compare directly from NPM, so that you can compare a proposed candidate version of your jsii package with an already-published version, by passing an argument that looks like `npm:\u003cpackage-specifier\u003e`. For example:\n\n```\njsii-diff npm:my-package@latest .\n```\n\nBy injecting a `;` into the `package-specifier` part of that command, jsii-diff can be tricked into running shell commands. For example:\n\n```\njsii-diff \"npm:lodash; touch /tmp/123\" .\n```\n\nThis allows anyone that can control the command-line arguments to jsii-diff to run arbitrary commands with the same permissions as the jsii-diff command itself.\n\n## Patches\nThis issue has been addressed in jsii-diff version 1.131.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.\n\n## Workarounds\nIf you are unable to update, make sure only trusted actors can control the arguments passed to jsii-diff.\n\n## References\nIf you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the [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.",
"id": "GHSA-wcx4-wpfv-mc5c",
"modified": "2026-08-07T18:15:47Z",
"published": "2026-08-07T18:15:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/aws/jsii/security/advisories/GHSA-wcx4-wpfv-mc5c"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15895"
},
{
"type": "WEB",
"url": "https://aws.amazon.com/security/security-bulletins/2026-057-aws"
},
{
"type": "PACKAGE",
"url": "https://github.com/aws/jsii"
},
{
"type": "WEB",
"url": "https://github.com/aws/jsii/releases/tag/v1.131.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "jsii-diff: Command Injection via npm: package argument"
}
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 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.