Vulnerability in brace-expansion (CVE-2026-45149)
Summary
Vulnerability in brace-expansion (CVE-2026-45149). Risk of unauthorized operations or information disclosure. Exploitable via max. Mitigation: upgrade to 5.0.6 or later.
Original description
The description as published by the source.
The brace-expansion library generates arbitrary strings containing a common prefix and suffix. From 5.0.0 to before 5.0.6, the max option was being applied too late. When expanding a single large numeric range like {1..10000000}, the sequence generation loop generates all 10 million intermediate elements before the max limit is applied With max=10, the output is correctly limited to 10 items, but the process still allocates ~505 MB and spends ~800ms building the full intermediate array. This vulnerability is fixed in 5.0.6.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
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 CVE-2026-45149 has been found in brace-expansion.
Attackers can target a specific entry point like max over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade brace-expansion to 5.0.6 or later.
If unsure, ask your IT team or search "brace-expansion CVE-2026-45149" on the vendor's site.
CVE-2026-45149 (brace-expansion) — CWE-400 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: max
Patched: 5.0.6 — apply immediately
Workaround: Ensure the string to be expanded doesn't contain more values than the desired max item count.
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.
A vulnerability (CWE-400) exists in brace-expansion. Attackers reach the vulnerable code path via max without authentication.
Check the vendor advisory for the affected versions of brace-expansion. Attack surface: max.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 5.0.6.
Workaround: Ensure the string to be expanded doesn't contain more values than the desired max item count.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '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
-
1Identify exposure identify
grep -r '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
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。 -
2Apply temporary workaround mitigate
Ensure the string to be expanded doesn't contain more values than the desired `max` item count.パッチが適用されるまでの応急処置として、Ensure the string to be expanded doesn't contain more values than the desired
maxitem count. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade brace-expansion to 5.0.6ステージング環境で 5.0.6 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。
-
4Post-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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-45149 node-brace-expansion
- Ubuntu UBUNTU-CVE-2026-45149 node-brace-expansion
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com