Quick answers
- Is CVE-2026-6338 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-6338 being exploited in the wild.
- How severe is CVE-2026-6338?
- Informational severity, with a CVSS score of 4.9, published 11 June 2026.
- Which products and versions are affected?
- Kong Gateway Enterprise 3.4, 3.10, 3.11, 3.12, 3.13, 3.14 series.
- Is there a fix for CVE-2026-6338?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-6338 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-6338?
- Check whether you run Kong Gateway Enterprise at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
Kong Gateway Enterprise is vulnerable to HTTP request smuggling (CWE-444) and request desynchronization. The root cause is a parsing flaw within Kong's HTTP request processing pipeline when handling untrusted HTTP/1.1 traffic. An unauthenticated remote attacker can exploit this by sending specially crafted HTTP requests that are interpreted differently by the Kong Gateway and the backend servers it protects. This can result in the attacker 'smuggling' a request to the backend, potentially leading to security filter bypass or cache poisoning. The vulnerability affects the 3.4 and 3.10 through 3.14 release series.
Affected products
- Kong Gateway Enterprise 3.4, 3.10, 3.11, 3.12, 3.13, 3.14 series
Timeline
- 2026-06-11: advisory: NVD and vendor advisory published