CVE-2026-6338 PUBLISHED

HTTP request smuggling in Kong Enteprise Gateway

Assigner: Kong
Reserved: 15.04.2026 Published: 11.06.2026 Updated: 11.06.2026

A HTTP request smuggling and desynchronization vulnerability affects Kong Gateway Enterprise 3.4, 3.10, 3.11, 3.12, 3.13, and 3.14 series. The vulnerability is caused by a parsing flaw in Kong’s HTTP request processing pipeline when handling untrusted HTTP/1.1 traffic.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:P/R:A/RE:M
CVSS Score: 4.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	High
Attack Complexity	Low	Integrity	None	Integrity	High
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Kong
Product	Kong Enterprise Gateway
Versions	Default: unaffected affected from 3.4.0.0 to 3.4.3.27 (excl.) affected from 3.10.0.0 to 3.10.0.12 (excl.) affected from 3.11.0.0 to 3.11.0.12 (excl.) affected from 3.12.0.0 to 3.12.0.7 (excl.) affected from 3.13.0.0 to 3.13.0.5 (excl.) affected from 3.14.0.0 to 3.14.0.4 (excl.)

References

https://support.konghq.com/support/s/article/CVE-2026-6338

Problem Types

CWE-444 Inconsistent interpretation of HTTP requests ('HTTP Request/Response smuggling') CWE

Impacts

CAPEC-33 HTTP Request Smuggling