CVE-2026-15895: CWE-78 Improper neutralization of special elements used in an OS command ('OS command injection') in AWS jsii
Bulletin ID: 2026-057-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/15/2026 12:00 PM PDT Description: 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. We identified CVE-2026-15895, an issue where specially formatted command line arguments can be used to execute shell commands via this tool. Impacted versions: < 1.131.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
AI Analysis
Technical Summary
The jsii-diff command line tool, used to compare API differences between jsii assemblies, improperly neutralizes special shell characters in command line arguments. Specifically, when a package specifier argument includes shell metacharacters such as a semicolon (';'), it can lead to execution of arbitrary shell commands with the permissions of the jsii-diff process. This vulnerability is identified as CWE-78 (OS command injection). The flaw affects versions prior to 1.131.0, and was addressed by AWS in version 1.131.0. The tool supports downloading packages directly from NPM, which is the vector for injection via the package specifier argument.
Potential Impact
An attacker who can control the command line arguments to jsii-diff can execute arbitrary shell commands with the same privileges as the jsii-diff process. This could lead to unauthorized system access or modification. The vulnerability requires local or limited access to run jsii-diff with crafted arguments, as indicated by the CVSS vector (AV:L). No known exploits in the wild have been reported.
Mitigation Recommendations
A patch is available in jsii-diff version 1.131.0. Users should upgrade to version 1.131.0 or later to remediate this vulnerability. If upgrading is not immediately possible, restrict access so that only trusted users can supply command line arguments to jsii-diff to prevent exploitation.
CVE-2026-15895: CWE-78 Improper neutralization of special elements used in an OS command ('OS command injection') in AWS jsii
Description
Bulletin ID: 2026-057-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/15/2026 12:00 PM PDT Description: 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. We identified CVE-2026-15895, an issue where specially formatted command line arguments can be used to execute shell commands via this tool. Impacted versions: < 1.131.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
CVSS v4.0
Score 8.4high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The jsii-diff command line tool, used to compare API differences between jsii assemblies, improperly neutralizes special shell characters in command line arguments. Specifically, when a package specifier argument includes shell metacharacters such as a semicolon (';'), it can lead to execution of arbitrary shell commands with the permissions of the jsii-diff process. This vulnerability is identified as CWE-78 (OS command injection). The flaw affects versions prior to 1.131.0, and was addressed by AWS in version 1.131.0. The tool supports downloading packages directly from NPM, which is the vector for injection via the package specifier argument.
Potential Impact
An attacker who can control the command line arguments to jsii-diff can execute arbitrary shell commands with the same privileges as the jsii-diff process. This could lead to unauthorized system access or modification. The vulnerability requires local or limited access to run jsii-diff with crafted arguments, as indicated by the CVSS vector (AV:L). No known exploits in the wild have been reported.
Mitigation Recommendations
A patch is available in jsii-diff version 1.131.0. Users should upgrade to version 1.131.0 or later to remediate this vulnerability. If upgrading is not immediately possible, restrict access so that only trusted users can supply command line arguments to jsii-diff to prevent exploitation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-07-15T17:56:36.976Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-057-aws/","vendor":"AWS"}]
Threat ID: 6a57dcf368715ace434afb58
Added to database: 07/15/2026, 19:18:11 UTC
Last enriched: 08/08/2026, 15:36:18 UTC
Last updated: 08/28/2026, 10:52:06 UTC
Views: 108
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