CVE-2026-87987: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-r6r3-x5p3-g7m8
Share
CWE-15
Published
Advisory Summary

CVE-2026-87987 is a CRITICAL security vulnerability vulnerability (CWE-15: External Control of System or Configuration Setting) affecting Software libraries in the Maven ecosystem. The weakness occurs when one or more system settings or configuration elements can be externally controlled by a user.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-87987 at a Glance

CVE Identifier CVE-2026-87987
GHSA Identifier GHSA-r6r3-x5p3-g7m8
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-15: External Control of System or Configuration Setting
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-87987

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-87987, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-15: External Control of System or Configuration Setting, where one or more system settings or configuration elements can be externally controlled by a user. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An arbitrary code execution vulnerability in Mistral Vibe allows an attacker to bypass command permission checks using environment variable assignments preceding allowlisted commands. These assignments are excluded from inspection, enabling attacker-controlled environment variables to cause arbitrary code execution without user approval.

References

NVD — CVE-2026-87987 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-87987
Software Security Information SECURITY
https://www.hiddenlayer.com/sai-security-advisory/2026-09-mistral-vibe5

Frequently Asked Questions

What is CVE-2026-87987?
CVE-2026-87987 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-15: External Control of System or Configuration Setting.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-87987?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-87987?
CVE-2026-87987 is classified under CWE-15: External Control of System or Configuration Setting (One or more system settings or configuration elements can be externally controlled by a user.).
How can I check Maven dependencies for CVE-2026-87987?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r6r3-x5p3-g7m8",
  "modified" : "2026-09-11T15:32:42Z",
  "published" : "2026-09-11T15:32:42Z",
  "aliases" : [ "CVE-2026-87987" ],
  "details" : "An arbitrary code execution vulnerability in Mistral Vibe allows an attacker to bypass command permission checks using environment variable assignments preceding allowlisted commands. These assignments are excluded from inspection, enabling attacker-controlled environment variables to cause arbitrary code execution without user approval.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-87987"
  }, {
    "type" : "WEB",
    "url" : "https://www.hiddenlayer.com/sai-security-advisory/2026-09-mistral-vibe5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-15" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T15:17:07Z"
  }
}