GHSA-v6h2-p8h4-qcjw CVE-2025-5889

brace-expansion Regular Expression Denial of Service vulnerability

Low npm

Severity: 1.3 / 10; Low · CVSS 4.0
Exploit chance (EPSS): 0.59%; Chance of exploitation in the next 30 days. Higher than 48.00% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-400 Uncontrolled Resource Consumption
Fix: 2.0.2; Upgrade brace-expansion to this version or later

Description

A vulnerability was found in juliangruber brace-expansion up to 1.1.11/2.0.1/3.0.0/4.0.0. It has been rated as problematic. Affected by this issue is the function expand of the file index.js. The manipulation leads to inefficient regular expression complexity. The attack may be launched remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 1.1.12, 2.0.2, 3.0.1 and 4.0.1 is able to address this issue. The name of the patch is a5b98a4f30d7813266b221435e1eaaf25a1b0ac5. It is recommended to upgrade the affected component.

Affected versions

npm

Package	Vulnerable	Fixed in
brace-expansion	`>= 2.0.0, <= 2.0.1`	No fix yet
brace-expansion	`>= 1.0.0, <= 1.1.11`	No fix yet
brace-expansion	1 listed versions	No fix yet
brace-expansion	1 listed versions	No fix yet
brace-expansion	`>= 2.0.0, < 2.0.2`	`2.0.2`
brace-expansion	`>= 1.0.0, < 1.1.12`	`1.1.12`
brace-expansion	`>= 3.0.0, < 3.0.1`	`3.0.1`
brace-expansion	`>= 4.0.0, < 4.0.1`	`4.0.1`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

brace-expansion npm → `2.0.2`

npm

npm install brace-expansion@2.0.2

yarn

yarn add brace-expansion@2.0.2

pnpm

pnpm add brace-expansion@2.0.2

Severity breakdown

CVSS 4.0 1.3

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

Attack vector: Network
Attack complexity: High
Attack requirements: None
Privileges required: Low
User interaction: None
Confidentiality (vulnerable system): None
Integrity (vulnerable system): None
Availability (vulnerable system): Low
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None
Exploit maturity: Proof of concept
Scope: X

CVSS 3.1 3.1

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

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Weakness

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it

Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Advisories

Fixes and patches

Packages

github.com/juliangruber/brace-expansion

Timeline

Jun 9, 2025 Published
Sep 10, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-qhr7-859c-m2p7 brace-expansion: DoS via uncontrolled recursion on nested brace groups causing stack exhaustion	High	Also affects brace-expansion
GHSA-q2hr-2g5m-vwhr brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service	Medium	Also affects brace-expansion
GHSA-6j4f-fj2g-mc7p brace-expansion: DoS via uncontrolled recursion in parseCommaParts causing stack exhaustion	High	Also affects brace-expansion
GHSA-rgw5-rvv9-x895 brace-expansion: DoS via unbounded intermediate arrays, bypassing the CVE-2026-14257 mitigation	High	Also affects brace-expansion
GHSA-mh99-v99m-4gvg brace-expansion: DoS via unbounded expansion length causing an out-of-memory process crash	High	Also affects brace-expansion
GHSA-3jxr-9vmj-r5cp brace-expansion: DoS via exponential-time expansion of consecutive non-expanding {} groups	High	Also affects brace-expansion
GHSA-jxxr-4gwj-5jf2 brace-expansion: Large numeric range defeats documented `max` DoS protection	High	Also affects brace-expansion
GHSA-f886-m6hf-6m8v brace-expansion: Zero-step sequence causes process hang and memory exhaustion	High	Also affects brace-expansion

Credits: carboneater, turi4200, viceice

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