Vulnerability Report

CVE-2026-6733

Title: HTTP/1.1 Response Queue Poisoning on Reused Keep-Alive Sockets

Arbitrary File Access

Proof Of Concept

No public PoC currently indexed for CVE-2026-6733.

CWE Category CWE-367
Published Date Jun 17, 2026
Modified Date Jun 27, 2026
Exploit Status Not Found
Score 3.7 CVSS v3.1
Exploit Probability (EPSS)
0.23%

Vulnerability Summary

CVE-2026-6733: Impact: Undici's HTTP/1.1 client is vulnerable to response queue poisoning on reused keep-alive sockets. An attacker-controlled upstream server can inject an unsolicited HTTP/1.1 response onto an idle socket after a request completes. When the client dispatches the next request on that socket, it associates the injected response with the new request, causing responses to be delivered to the wrong requests. This requires an attacker-controlled or compromised upstream HTTP/1.1 server and keep-alive connection reuse. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: Disable keep-alive connection reuse by setting keepAliveTimeout: 0 on the Client or Pool.

Impacted Vendors

N
nodejs 1

Reference Links

https://cna.openjsf.org/security-advisories.html https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52 https://hackerone.com/reports/3582376
CVSS v3.1
Source Entity ce714d77-add3-4f53-aff5-83d477b104bb
Severity LOW
3.7
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-6733 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected Stack

No specific products linked.