CVE-2026-63384

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Source
https://cve.org/CVERecord?id=CVE-2026-63384
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63384.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-63384
Aliases
  • GHSA-45c6-qx49-89m8
Downstream
Published
2026-08-20T17:53:08Z
Modified
2026-09-11T08:36:40Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.
Details

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-190"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63384.json"
}
References

Affected packages

Git / github.com/libevent/libevent

Affected ranges

Type
GIT
Repo
https://github.com/libevent/libevent
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
df3ecad3a040fd6d4fad4287defe113395de6fd7
Fixed
79ddfb460847999b807cba76d04e73891f29c6ee
Fixed
109c16499282959d70f56ec3baf4c8b1e6646bda
Fixed
5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "2.2.0-alpha"
        },
        {
            "fixed": "2.2.2-alpha"
        },
        {
            "introduced": "0"
        },
        {
            "fixed": "2.1.13"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

release-1.*
release-1.1b
release-2.*
release-2.0.1-alpha
release-2.0.10-stable
release-2.0.3-alpha
release-2.0.4-alpha
release-2.0.5-beta
release-2.0.6-rc
release-2.0.7-rc
release-2.0.8-rc
release-2.0.9-rc
release-2.1.1-alpha
release-2.1.10-stable
release-2.1.11-stable
release-2.1.12-stable
release-2.1.2-alpha
release-2.1.3-alpha
release-2.1.4-alpha
release-2.1.5-beta
release-2.1.6-beta
release-2.1.7-rc
release-2.1.8-stable
release-2.1.9-beta
release-2.2.1-alpha

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63384.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "65618021557916598666749967159040448195",
            "length": 250
        },
        "id": "CVE-2026-63384-05d7cf03",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/109c16499282959d70f56ec3baf4c8b1e6646bda",
        "target": {
            "file": "event_tagging.c",
            "function": "evtag_unmarshal_header"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "159443554126248192493229143747497657830",
            "length": 554
        },
        "id": "CVE-2026-63384-09212634",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/df3ecad3a040fd6d4fad4287defe113395de6fd7",
        "target": {
            "file": "test/regress_http.c",
            "function": "http_check_transfer_encoding_test"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "65618021557916598666749967159040448195",
            "length": 250
        },
        "id": "CVE-2026-63384-79cf092b",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416",
        "target": {
            "file": "event_tagging.c",
            "function": "evtag_unmarshal_header"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "130688092411103881779793319185293442532",
                "35591852254511256822037719077016828240",
                "149333174035468761482274091843112180090",
                "167782302790249760667996112209708432798"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-63384-91b26bd8",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/109c16499282959d70f56ec3baf4c8b1e6646bda",
        "target": {
            "file": "event_tagging.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "270762094980121927552802584929566056086",
                "37564212311334647331345684303177453724",
                "168570413533780985513641597969239978857"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-63384-923050c6",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/df3ecad3a040fd6d4fad4287defe113395de6fd7",
        "target": {
            "file": "test/regress_http.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "270762094980121927552802584929566056086",
                "37564212311334647331345684303177453724",
                "168570413533780985513641597969239978857"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-63384-979e5bed",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/79ddfb460847999b807cba76d04e73891f29c6ee",
        "target": {
            "file": "test/regress_http.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "130688092411103881779793319185293442532",
                "35591852254511256822037719077016828240",
                "149333174035468761482274091843112180090",
                "167782302790249760667996112209708432798"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-63384-b9e1d770",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/5e3c6ebe342b34c5a9bcf48e9a32ad6708b9c416",
        "target": {
            "file": "event_tagging.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "159443554126248192493229143747497657830",
            "length": 554
        },
        "id": "CVE-2026-63384-ebc5ab94",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libevent/libevent/commit/79ddfb460847999b807cba76d04e73891f29c6ee",
        "target": {
            "file": "test/regress_http.c",
            "function": "http_check_transfer_encoding_test"
        }
    }
]
vanir_signatures_modified 
"2026-09-11T08:36:40Z"