eslint-9.39.4.tgz: 2 vulnerabilities (highest severity is: 9.8)

[mend-for-github-com]

Vulnerable Library - eslint-9.39.4.tgz

Path to dependency file: /package.json

Path to vulnerable library: /package.json

Vulnerabilities

Vulnerability	Severity	CVSS	Dependency	Type	Fixed in (eslint version)	Remediation Possible**
CVE-2026-33228	Critical	9.8	flatted-3.4.1.tgz	Transitive	N/A*	❌
CVE-2026-33750	Medium	6.5	brace-expansion-1.1.12.tgz	Transitive	N/A*	❌

*For some transitive vulnerabilities, there is no version of direct dependency with a fix. Check the "Details" section below to see if there is a version of transitive dependency where vulnerability is fixed.

**In some cases, Remediation PR cannot be created automatically for a vulnerability despite the availability of remediation

Details

CVE-2026-33228

Vulnerable Library - flatted-3.4.1.tgz

A super light and fast circular JSON parser.

Library home page: https://registry.npmjs.org/flatted/-/flatted-3.4.1.tgz

Path to dependency file: /package.json

Path to vulnerable library: /package.json

Dependency Hierarchy:

• eslint-9.39.4.tgz (Root Library)
  • file-entry-cache-8.0.0.tgz
    • flat-cache-4.0.1.tgz
      • ❌ flatted-3.4.1.tgz (Vulnerable Library)

Found in base branch: main

Vulnerability Details

flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "proto" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.
Mend Note: The description of this vulnerability differs from MITRE.

Publish Date: 2026-03-20

URL: CVE-2026-33228

CVSS 3 Score Details (9.8)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: High
  • Integrity Impact: High
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-03-20

Fix Resolution: https://github.com/WebReflection/flatted.git - v3.4.2

CVE-2026-33750

Vulnerable Library - brace-expansion-1.1.12.tgz

Brace expansion as known from sh/bash

Library home page: https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz

Path to dependency file: /package.json

Path to vulnerable library: /package.json

Dependency Hierarchy:

• eslint-9.39.4.tgz (Root Library)
  • minimatch-3.1.5.tgz
    • ❌ brace-expansion-1.1.12.tgz (Vulnerable Library)

Found in base branch: main

Vulnerability Details

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13, a brace pattern with a zero step value (e.g., "{1..2..0}") causes the sequence generation loop to run indefinitely, making the process hang for seconds and allocate heaps of memory. Versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13 fix the issue. As a workaround, sanitize strings passed to "expand()" to ensure a step value of "0" is not used.

Publish Date: 2026-03-27

URL: CVE-2026-33750

CVSS 3 Score Details (6.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-03-27

Fix Resolution: https://github.com/juliangruber/brace-expansion.git - v2.0.3,https://github.com/juliangruber/brace-expansion.git - v3.0.2,https://github.com/juliangruber/brace-expansion.git - v5.0.5,https://github.com/juliangruber/brace-expansion.git - v1.1.13