libssh2 – Integer Overflow in publickey Subsystem Attribute Allocation_CVE-2026-58050

{
    "lastseen": "",
    "description": "libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.",
    "published": "2026-06-28T01:32:53.582Z",
    "modified": "2026-06-28T01:32:53.582Z",
    "type": "cve",
    "title": "libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation",
    "source": "VulnCheck",
    "references": "https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc\nhttps://github.com/libssh2/libssh2/blob/master/src/publickey.c\nhttps://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation",
    "id": "CVE-2026-58050",
    "bulletinFamily": "",
    "cwe": [
        "CWE-190"
    ],
    "cvelist": null,
    "sourceData": "libssh2 libssh2 0",
    "sourceHref": "",
    "cvss": {
        "score": 7,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/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": "libssh2",
    "version": "0",
    "vendor": "libssh2",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}