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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3	Third Party Advisory
https://metacpan.org/release/KAZEBURO/Gazelle-0.50/changes	Release Notes
https://security.metacpan.org/patches/G/Gazelle/0.49/CVE-2026-40562-r1.patch	Patch
http://www.openwall.com/lists/oss-security/2026/05/06/7	Mailing List Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:kazeburo:gazelle:*:*:*:*:*:perl:*:*

History

No history.

Information

Published : 2026-05-06 13:16

Updated : 2026-06-17 10:45

NVD link : CVE-2026-40562

Mitre link : CVE-2026-40562

CVE.ORG link : CVE-2026-40562

JSON object : View

Products Affected

kazeburo

gazelle

CWE

CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

{"id": "CVE-2026-40562", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40562", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-06T14:14:25.637199Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "affectedData": [{"repo": "https://github.com/kazeburo/Gazelle", "vendor": "KAZEBURO", "product": "Gazelle", "versions": [{"status": "affected", "version": "0", "versionType": "custom", "lessThanOrEqual": "0.49"}], "packageName": "Gazelle", "programFiles": ["lib/Plack/Handler/Gazelle.pm", "lib/Plack/Handler/Gazelle.xs"], "collectionURL": "https://cpan.org/modules", "defaultStatus": "unaffected", "programRoutines": [{"name": "Plack::Handler::Gazelle::run"}, {"name": "lib/Plack/Handler/Gazelle.xs::_parse_http_request"}]}]}], "published": "2026-05-06T13:16:09.110", "references": [{"url": "https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3", "tags": ["Third Party Advisory"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://metacpan.org/release/KAZEBURO/Gazelle-0.50/changes", "tags": ["Release Notes"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://security.metacpan.org/patches/G/Gazelle/0.49/CVE-2026-40562-r1.patch", "tags": ["Patch"], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "http://www.openwall.com/lists/oss-security/2026/05/06/7", "tags": ["Mailing List", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "description": [{"lang": "en", "value": "CWE-444"}]}], "descriptions": [{"lang": "en", "value": "Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence.\n\nGazelle 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.\n\nAn attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy."}], "lastModified": "2026-06-17T10:45:27.267", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:kazeburo:gazelle:*:*:*:*:*:perl:*:*", "vulnerable": true, "matchCriteriaId": "F2360CF4-CAB8-4DC7-B595-C7501D7EC17C", "versionEndExcluding": "0.50"}], "operator": "OR"}]}], "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}