# CVE-2026-102276: brace-expansion stack exhaustion denial of service

Source: https://junglewise.ai/threats/cve-2026-102276-the-brace-expansion-library-generates-arbitrary-strings  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-28. Updated: 2026-09-28  
License: CC BY 4.0 with a link back

CVE-2026-102276 · Severity: high · CVSS 7.5 · Published 2026-09-28

The brace-expansion library parses brace-pattern strings into expanded output, commonly used in command-line tools and build systems. A remote attacker can craft malicious input patterns that exhaust the native stack during parsing, crashing the Node.js process and causing a denial of service. No data exposure or privilege escalation occurs; the impact is process termination and service outage.

Technologies: [Juliangruber Brace-Expansion](https://junglewise.ai/threats/technologies/juliangruber-brace-expansion), [brace-expansion (npm)](https://junglewise.ai/threats/technologies/brace-expansion). Vendors: [Juliangruber](https://junglewise.ai/threats/vendors/juliangruber), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-102276 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102276 being exploited in the wild.

**How severe is CVE-2026-102276?** High severity, with a CVSS score of 7.5, published 28 September 2026.

**Which products and versions are affected?** Juliangruber Brace-Expansion before 1.1.19, 2.1.5, 3.0.7, and 5.0.10; brace-expansion (npm) SEMVER:introduced=4.0.0,fixed=5.0.10.

**Is there a fix for CVE-2026-102276?** Yes. brace-expansion (npm): upgrade to 5.0.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-102276 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-102276?** Check whether you run Juliangruber Brace-Expansion or brace-expansion (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- brace-expansion (npm): upgrade to 5.0.10 or later

  ```sh
  npm install brace-expansion@5.0.10
  ```


## Technical details

The vulnerability is a stack exhaustion flaw in the parseCommaParts function, which processes brace patterns recursively. Two attack paths exist: (1) deeply nested brace groups cause recursive stack exhaustion at ~7,000 groups, and (2) arrays passed to push.apply() with ~125,000 elements overflow the stack via argument expansion, both occurring during parsing before output is generated. The fix converts parseCommaParts to iterative logic and replaces push.apply with element-by-element appending.

## Affected products

- juliangruber brace-expansion before 1.1.19, 2.1.5, 3.0.7, and 5.0.10

## Identifiers

- CVE-2026-102276
- GHSA-6j4f-fj2g-mc7p

## Timeline

- 2026-09-28: disclosed
- 2026-09-14: patched: Fix commits merged to main branch

## References

- [https://github.com/juliangruber/brace-expansion/commit/0bcbfc0a5928c3073d48f42999d1ce4fc1c42fbc](https://github.com/juliangruber/brace-expansion/commit/0bcbfc0a5928c3073d48f42999d1ce4fc1c42fbc)
- [https://github.com/juliangruber/brace-expansion/commit/316359e6019c39b3254c8ba8e25dc586a480652c](https://github.com/juliangruber/brace-expansion/commit/316359e6019c39b3254c8ba8e25dc586a480652c)

## Related threats

- [brace-expansion stack exhaustion in deeply nested brace groups](https://junglewise.ai/threats/cve-2026-102278-the-brace-expansion-library-generates-arbitrary-strings)
- [brace-expansion quadratic CPU consumption denial of service](https://junglewise.ai/threats/cve-2026-102277-the-brace-expansion-library-generates-arbitrary-strings)
- [juliangruber brace-expansion Denial of Service via unbounded arrays](https://junglewise.ai/threats/cve-2026-69152-juliangruber-brace-expansion-denial-of-service-via-unbounded)
- [juliangruber brace-expansion denial of service via memory exhaustion](https://junglewise.ai/threats/cve-2026-14257-juliangruber-brace-expansion-denial-of-service-via-memory)
- [juliangruber brace-expansion denial of service in expand function](https://junglewise.ai/threats/cve-2026-13149-juliangruber-brace-expansion-denial-of-service-in-expand-function)