{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63379",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-16T17:39:30.170Z",
        "datePublished": "2026-08-20T17:55:00.789Z",
        "dateUpdated": "2026-08-20T17:55:00.789Z"
    },
    "containers": {
        "cna": {
            "title": "Libevent: HTTP Header smuggling",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-444",
                            "lang": "en",
                            "description": "CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "LOW",
                        "vulnIntegrityImpact": "LOW",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 6.3,
                        "baseSeverity": "MEDIUM",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/libevent/libevent/security/advisories/GHSA-2gmv-p5m7-98p6"
                },
                {
                    "name": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/libevent/libevent/commit/87e8e44fa774e9677b089b1a5114ee68aefa1636"
                },
                {
                    "name": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/libevent/libevent/commit/b847071141b3827900d536594ec9045eb0a4c485"
                },
                {
                    "name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
                },
                {
                    "name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
                }
            ],
            "affected": [
                {
                    "vendor": "libevent",
                    "product": "libevent",
                    "versions": [
                        {
                            "version": "< 2.1.13",
                            "status": "affected"
                        },
                        {
                            "version": ">= 2.2.0-alpha, < 2.2.2-alpha",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-20T17:55:00.789Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req->input_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha."
                }
            ],
            "source": {
                "advisory": "GHSA-2gmv-p5m7-98p6",
                "discovery": "UNKNOWN"
            }
        }
    }
}