By permanently omitting the final control-response line, a malicious FTP,
IMAP, POP3, or SMTP server can exploit libcurl and completely bypass its
configured transfer timeout mechanism, indefinitely blocking all concurrent
transfers bound to the same multi-handle.
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8927-1 curl vulnerabilities
Ubuntu USN Ubuntu USN USN-8927-2 curl vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 20 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in curl. When communicating with a malicious server using protocols such as FTP, IMAP, POP3, or SMTP, the server can trigger an infinite loop by continuously transmitting data while omitting the final control response line. This behavior bypasses configured transfer timeouts, indefinitely blocking concurrent transfers and resulting in a Denial of Service (DoS). By permanently omitting the final control-response line, a malicious FTP, IMAP, POP3, or SMTP server can exploit libcurl and completely bypass its configured transfer timeout mechanism, indefinitely blocking all concurrent transfers bound to the same multi-handle.
Title curl: curl: never-ending loop via server response omission never-ending loop via server response omission
References

Sun, 18 Oct 2026 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Curl
Curl curl
Vendors & Products Curl
Curl curl

Sat, 17 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in curl. When communicating with a malicious server using protocols such as FTP, IMAP, POP3, or SMTP, the server can trigger an infinite loop by continuously transmitting data while omitting the final control response line. This behavior bypasses configured transfer timeouts, indefinitely blocking concurrent transfers and resulting in a Denial of Service (DoS).
Title curl: curl: never-ending loop via server response omission
Weaknesses CWE-835
References
Metrics threat_severity

None

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Low


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: curl

Published:

Updated: 2026-10-20T20:19:14.672Z

Reserved: 2026-09-16T08:12:45.613Z

Link: CVE-2026-92387

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-20T21:17:21.133

Modified: 2026-10-20T21:17:21.133

Link: CVE-2026-92387

cve-icon Redhat

Severity : Low

Publid Date: 2026-10-14T12:00:00Z

Links: CVE-2026-92387 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-20T23:00:23Z

Weaknesses