CVE-2026-40562CWE-444

Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence

High · published May 6, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
42.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00501 · 42.0th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-05-06T12:36Z
EPSS history
Timeline
  • 06 MAY 12:36Z
    Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence
    cvelistv5