CVE-2026-126345
basic-ftp: Uncaught TypeError in MLSD directory-listing parser via __proto__ fact name causes DoS in Client.list()
- Medium 5.3
Description
basic-ftp is an FTP client for Node.js. Prior to 6.2.4, the MLSD directory-listing parser in src/parseListMLSD.ts uses untrusted fact names from the FTP server as keys in the plain-object factHandlersByName dictionary without checking that the resolved property is an own handler. A fact named __proto__ therefore resolves to Object.prototype, bypasses the missing-handler guard, and is called as though it were a function, producing a TypeError. The error propagates through Client.list() and APIs that depend on it because it is not an FTPError. A malicious or compromised FTP server, or an on-path attacker on a plaintext FTP session, can make the affected operation reject, and the Node.js process terminates under the default behavior in Node.js 15 and later only if the application leaves that rejection unhandled. This issue is fixed in version 6.2.4.
Key facts
- Published
- 12 Nov 2026
- Last changed
- 12 Nov 2026
- Assigned by
- GitHub_M
- EPSS
- 0.495% likely to be exploited in the next 30 days, higher than 43.059% of CVEs (scores for 15 Nov 2026)
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 5.3CVSS 3.1, Mediumfrom the CNA (GitHub_M)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| patrickjuchli | basic-ftp |
|
Timeline
- 12 Nov 2026 Published