How severe is CVE-2026-6338?

CVE-2026-6338 has a CVSS 4.0 base score of 4.9, rated medium severity.

Is CVE-2026-6338 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-6338?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-6338 have an EU (EUVD) identifier?

Yes. CVE-2026-6338 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36246.

When was CVE-2026-6338 published?

CVE-2026-6338 was published on 2026-06-11 and last updated on 2026-06-17.

CVE-2026-6338

CVE-2026-6338 is a medium-severity vulnerability with a CVSS 4.0 base score of 4.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: Medium (CVSS 4.0 base score 4.9)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-36246
Weakness: CWE-444
Published: 2026-06-11
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-6338?: 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.
How severe is CVE-2026-6338?: CVE-2026-6338 has a CVSS 4.0 base score of 4.9, rated medium severity.
Is CVE-2026-6338 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-6338?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-6338 have an EU (EUVD) identifier?: Yes. CVE-2026-6338 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36246.
When was CVE-2026-6338 published?: CVE-2026-6338 was published on 2026-06-11 and last updated on 2026-06-17.

References

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

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