CVE-2026-92387
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).
Statement
This vulnerability is rated as Low severity by Red Hat because successful exploitation requires connecting to an untrusted server under specific network throughput conditions and only results in denial of service for concurrent transfers. The standard curl command-line utility is unaffected, confining the flaw to applications utilizing libcurl asynchronous multi-handles. Additionally, the issue is limited to transactions using interactive protocols such as FTP, IMAP, POP3, or SMTP where an adversarial endpoint continuously streams data without final status terminators.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.7 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | Low | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
Acknowledgements
Red Hat would like to thank Joshua Rogers (Aisle Research) for reporting this issue.
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