Vulnerability in piscina (CVE-2026-55388)
Summary
Vulnerability in piscina (CVE-2026-55388). Successful exploitation can lead to full system takeover. Exploitable via POST /upload. Mitigation: upgrade to 6.0.0-rc.2 or later.
Original description
The description as published by the source.
piscina is a node.js worker pool implementation. Prior to 6.0.0-rc.2, 5.2.0, and 4.9.3, piscina's constructor and run() paths read the filename option via plain member access. Both reads fall through the prototype chain when the caller's options object doesn't have filename as an own property. When Object.prototype.filename is polluted upstream the inherited value flows to worker_threads.Worker import and the attacker's .mjs runs in the worker. This vulnerability is fixed in 6.0.0-rc.2, 5.2.0, and 4.9.3.
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-2026-55388 has been found in piscina.
Attackers can target a specific entry point like POST /upload over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.1/10.
What to do: upgrade piscina to 6.0.0-rc.2 or later.
If unsure, ask your IT team or search "piscina CVE-2026-55388" on the vendor's site.
CVE-2026-55388 (piscina) — CWE-1321 / CVSS v3 8.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /upload / POST /api/settings / POST /api/process / piscina
Patched: 6.0.0-rc.2 — 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.
A vulnerability (CWE-1321) exists in piscina. Attackers reach the vulnerable code path via POST /upload without authentication.
Check the vendor advisory for the affected versions of piscina. Attack surface: POST /upload / POST /api/settings / POST /api/process / piscina.
Severity: High (CVSS 8.1/10). Successful exploitation can lead to full system takeover.
Update to 6.0.0-rc.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /upload requests with malformed payloads or SQL meta-characters. Run grep -r 'piscina' . 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 'piscina' . | 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
piscinaを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /upload' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /uploadへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade piscina to 6.0.0-rc.2ステージング環境で 6.0.0-rc.2 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と、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /upload on staging to confirm patch closes the vector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 Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com