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 RFC 7230 3.3.3, Transfer-Encoding must take precedence. An attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.
Vulnerability class: HTTP Request Smuggling
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.005 (40.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Kazeburo Gazelle — versions 0
Weakness classification (CWE)
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.