Vulnerability in node-brace-expansion (UBUNTU-CVE-2026-14257)

Summary

Vulnerability in node-brace-expansion (UBUNTU-CVE-2026-14257). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.0.8 or later.

Original description

The description as published by the source.

brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining multiple brace groups, an attacker keeps the result count under the limit while making each result progressively longer, so total memory scales with both count and string length until the process hits a fatal, uncatchable out-of-memory error. About 7.5 KB of input ('{a,b}'.repeat(1500)) crashes a default Node.js process. Any application that passes attacker-influenced strings to brace-expansion.expand() - directly or transitively via minimatch / glob brace patterns - can be crashed by a small request. Fixed in 5.0.8 by adding a maxLength option (default 4,000,000) that bounds accumulated output and intermediate arrays.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2026-14257 has been found in node-brace-expansion.
Risk of unauthorized operations or information disclosure.
What to do: upgrade node-brace-expansion to 5.0.8 or later.
If unsure, ask your IT team or search "node-brace-expansion UBUNTU-CVE-2026-14257" on the vendor's site.

UBUNTU-CVE-2026-14257 (node-brace-expansion)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.0.8 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in node-brace-expansion.

📍 Affected scope

Check the vendor advisory for the affected versions of node-brace-expansion.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 5.0.8.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'node-brace-expansion' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'node-brace-expansion' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で node-brace-expansion を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade node-brace-expansion to 5.0.8
```
ステージング環境で 5.0.8 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。