FTP command injection via unsanitized path delimiters
Published Apr 9, 2026 · Updated Apr 9, 2026
FTP command injection in basic-ftp 5.2.0 allows remote attackers to issue arbitrary FTP commands through crafted path parameters. The protectWhitespace() helper returns paths containing CR or LF unchanged, and FtpContext.send() appends CRLF before writing each command to the control socket. Exploitation requires a consuming application to pass attacker-controlled paths; injected commands run with the FTP session's permissions and can read, write, or delete server files.
Summary
What happened
FTP command injection in basic-ftp 5.2.0 allows remote attackers to issue arbitrary FTP commands through crafted path parameters. The protectWhitespace() helper returns paths containing CR or LF unchanged, and FtpContext.send() appends CRLF before writing each command to the control socket. Exploitation requires a consuming application to pass attacker-controlled paths; injected commands run with the FTP session's permissions and can read, write, or delete server files.
The record
- CVE
- CVE-2026-39983
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- Patrick Juchli
- Product
- basic-ftp
- Classifications
- CWE-93
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 5.2.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-chqc-8p9q-pq6q embedded proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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