What is CVE-2026-40562?

CVE-2026-40562 is a high-severity vulnerability in Kazeburo Gazelle, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 7.5/10. Published 2026-05-06.

How severe is CVE-2026-40562?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Kazeburo Gazelle

CVE-2026-40562

Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Gazelle incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per…

Vulnerability class: HTTP Request Smuggling

EPSS: 0.000 (11.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Kazeburo Gazelle — versions 0

Weakness classification (CWE)

CWE-444 — Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling)

References

9b29abf9-4ab0-4765-b253-1875cd9b441e (Third Party Advisory)
9b29abf9-4ab0-4765-b253-1875cd9b441e (Patch, patch)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)

Frequently asked questions

What is CVE-2026-40562?: CVE-2026-40562 is a high-severity vulnerability in Kazeburo Gazelle, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 7.5/10. Published 2026-05-06.
How severe is CVE-2026-40562?: High severity. CVSS v3 base score is 7.5 out of 10.