CVE-2026-6733
Description
A flaw was found in undici. An attacker-controlled upstream server can exploit a vulnerability in Undici's HTTP/1.1 client, specifically related to response queue poisoning on reused keep-alive sockets. This allows the attacker to inject an unsolicited HTTP/1.1 response onto an idle socket. Consequently, when the client dispatches a new request on that socket, it may associate the injected response with the new request, leading to responses being delivered to unintended recipients or requests. This could result in a low impact on data integrity.
Statement
Low: A flaw in Undici's HTTP/1.1 client, as used in various Red Hat products, allows an attacker-controlled upstream server to inject unsolicited responses onto reused keep-alive sockets. This can lead to incorrect response delivery, potentially impacting data integrity, but requires a compromised server and active keep-alive connections.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 3.7 |
| 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 | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context; Bypass Protection Mechanism
An attacker can access any functionality that is inadvertently accessible to the source.
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