Which versions of jsii-diff are affected by CVE-2026-15895?

AWS jsii-diff prior to version 1.131.0 is vulnerable to code injection attacks when development teams use the tool with untrusted package sources, creating a material risk to developer systems and…. A patch is available.

Is there a public PoC exploit available for CVE-2026-15895?

Yes, a public proof-of-concept exploit is available for CVE-2026-15895. Prioritise patching immediately. EPSS: 1.2%.

How to fix or mitigate CVE-2026-15895?

Within 24 hours, inventory all jsii-diff installations in your development environment, CI/CD systems, and build infrastructure to identify versions prior to 1.131.0, and communicate the vulnerability and patch availability to all affected teams. Within 7 days, deploy jsii-diff version 1.131.0 across all systems, verify successful installation through dependency audits, and confirm that all build pipelines are running the patched version. Within 30 days, review development environment logs and package sources for any suspicious activity or malicious package specifications processed by jsii-diff, and implement input validation or package source restrictions to prevent similar risks.

jsii-diff CVE-2026-15895

Q: What is the CVSS score of CVE-2026-15895?

CVE-2026-15895 has a CVSS 4.0 base score of 8.4 (High). CVSS vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 1.2%.

EUVD-2026-44768 HIGH

OS Command Injection (CWE-78)

2026-07-15 ff89ba41-3aa1-4d27-914a-91399e9639e5

GHSA-h738-vh6g-q8gh

GHSA-wcx4-wpfv-mc5c

Command Injection Node.js

8.4

CVSS 4.0 · Vendor: ff89ba41-3aa1-4d27-914a-91399e9639e5

Severity by source

Vendor (ff89ba41-3aa1-4d27-914a-91399e9639e5) PRIMARY

8.4 HIGH

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

7.8 HIGH

Local CLI tool requiring a victim to run it with an attacker-controlled npm: argument, so AV:L and UI:R; command injection yields full C/I/A impact without prior authentication.

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

4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (ff89ba41-3aa1-4d27-914a-91399e9639e5).

CVSS VectorVendor: ff89ba41-3aa1-4d27-914a-91399e9639e5

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

Patch available

Jul 15, 2026 - 21:18 EUVD

Source Code Evidence Fetched

Jul 15, 2026 - 19:31 vuln.today

Analysis Generated

Jul 15, 2026 - 19:31 vuln.today

CVE Published

Jul 15, 2026 - 19:16 cve.org

HIGH 8.4

DescriptionCVE.org

OS command injection in the npm package loading component in AWS jsii-diff before 1.131.0 might allow context-dependent attackers to execute arbitrary commands via crafted package specifiers passed to the npm: source argument.

To mitigate this issue, users should upgrade to jsii-diff v1.131.0 or later.

Articles & Coverage 1

News 4 New Node.js Vulnerabilities - 4 High Severity, 3 With POC Jul 16, 2026

AnalysisAI

OS command injection in AWS jsii-diff before 1.131.0 lets a context-dependent attacker execute arbitrary shell commands when a victim runs the tool against an attacker-controlled 'npm:' source specifier. The npm package-loading component fails to sanitize the package specifier before passing it to a shell, so a crafted specifier is interpreted as a command. No public exploit has been identified at time of analysis and it is not listed in CISA KEV; a vendor-released patch (v1.131.0) is available.

Technical ContextAI

jsii-diff is a comparison utility from AWS's jsii toolchain (the technology underpinning AWS CDK's multi-language construct libraries), used to diff two versions of a jsii assembly. It accepts assemblies from several sources, including an 'npm:' source that loads a package by specifier. The root cause is CWE-78 (OS Command Injection): the npm loading component builds a shell command incorporating the user-supplied package specifier without adequate escaping or a shell-free exec, so metacharacters in the specifier break out into the underlying shell. This is a Node.js/npm CLI tooling issue rather than a network service exposure.

RemediationAI

Vendor-released patch: jsii-diff v1.131.0 - upgrade to v1.131.0 or later (see https://github.com/aws/jsii/releases/tag/v1.131.0 and the AWS bulletin https://aws.amazon.com/security/security-bulletins/2026-057-aws/). Until upgrading, do not pass untrusted or externally-influenced values to the 'npm:' source argument of jsii-diff, and avoid running it against attacker-controllable package specifiers in automated CI/CD pipelines; restrict who can supply jsii-diff arguments and treat any 'npm:' input as untrusted. The trade-off of avoiding the 'npm:' source is loss of the ability to diff assemblies loaded directly from npm, requiring you to fetch and reference assemblies from a trusted local path instead.