Granian: Unauthenticated DoS via WebSocket subprotocol header panic_CVE-2026-42544

7.5 / 10

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whose Sec-WebSocket-Protocol header contains non-ASCII bytes. The crash happens in Granian's WebSocket scope construction path, before the ASGI application is invoked. This vulnerability is fixed in 2.7.4.

Basic Information

ID CVE-2026-42544

Source GitHub_M

Published May 12, 2026 at 21:46

Affected Product

Vendor emmett-framework

Product granian

Version >= 1.2.0, < 2.7.4

Affected Versions emmett-framework granian >= 1.2.0, < 2.7.4

CWE Classification

CWE-20 CWE-248 CWE-400

References

github.com /emmett-framework/granian/security/advisories/GHSA-vrg7-482j-p6f6

{
    "lastseen": "",
    "description": "Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whose Sec-WebSocket-Protocol header contains non-ASCII bytes. The crash happens in Granian's WebSocket scope construction path, before the ASGI application is invoked. This vulnerability is fixed in 2.7.4.",
    "published": "2026-05-12T21:46:19.734Z",
    "modified": "2026-05-12T21:46:19.734Z",
    "type": "cve",
    "title": "Granian: Unauthenticated DoS via WebSocket subprotocol header panic",
    "source": "GitHub_M",
    "references": "https://github.com/emmett-framework/granian/security/advisories/GHSA-vrg7-482j-p6f6",
    "id": "CVE-2026-42544",
    "bulletinFamily": "",
    "cwe": [
        "CWE-20",
        "CWE-248",
        "CWE-400"
    ],
    "cvelist": null,
    "sourceData": "emmett-framework granian >= 1.2.0, < 2.7.4",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "granian",
    "version": ">= 1.2.0, < 2.7.4",
    "vendor": "emmett-framework",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}