CVE-2026-40562

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

HIGH
7.5
CVSS Score
Published: May 6, 2026 at 12:36 PM UTC
Updated: October 26, 2026 at 07:10 PM UTC
1 product affected across 1 vendorGazelle

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Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.50

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-444

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