Vulnerability in basic-ftp (CVE-2026-44240)
Summary
Vulnerability in basic-ftp (CVE-2026-44240). Risk of unauthorized operations or information disclosure. Exploitable via FtpContext._partialResponse. Mitigation: upgrade to 5.3.1 or later.
Original description
The description as published by the source.
basic-ftp is an FTP client for Node.js. Prior to 5.3.1, basic-ftp is vulnerable to client-side denial of service when parsing FTP control-channel multiline responses. A malicious or compromised FTP server can send an unterminated multiline response during the initial FTP banner phase, before authentication. The client keeps appending attacker-controlled data into FtpContext._partialResponse and repeatedly reparses the accumulated buffer without enforcing a maximum control response size. As a result, an application using basic-ftp can remain stuck in connect() while memory and CPU usage grow under attacker-controlled input. This can lead to process-level denial of service, container OOM kills, worker restarts, queue backlog, or service degradation in applications that automatically connect to FTP endpoints. This vulnerability is fixed in 5.3.1.
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-2026-44240 has been found in basic-ftp.
Attackers can target a specific entry point like FtpContext._partialResponse over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade basic-ftp to 5.3.1 or later.
If unsure, ask your IT team or search "basic-ftp CVE-2026-44240" on the vendor's site.
CVE-2026-44240 (basic-ftp) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: FtpContext._partialResponse / FtpContext / _partialResponse / _onControlSocketData
Patched: 5.3.1 — 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-400) exists in basic-ftp. Attackers reach the vulnerable code path via FtpContext._partialResponse without authentication.
Check the vendor advisory for the affected versions of basic-ftp. Attack surface: FtpContext._partialResponse / FtpContext / _partialResponse / _onControlSocketData.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 5.3.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'basic-ftp' . 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
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1Identify exposure identify
grep -r 'basic-ftp' . | 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
basic-ftpを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade basic-ftp to 5.3.1ステージング環境で 5.3.1 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。
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3Post-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-2026-44240 node-proxy-agents
- Ubuntu UBUNTU-CVE-2026-44240 node-proxy-agents
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com