libssh2 – Heap Buffer Over-read via sftp_symlink() in sftp.c_CVE-2025-15661

{
    "lastseen": "",
    "description": "libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.",
    "published": "2026-06-18T20:18:29.475Z",
    "modified": "2026-06-18T20:19:34.109Z",
    "type": "cve",
    "title": "libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c",
    "source": "VulnCheck",
    "references": "https://github.com/libssh2/libssh2/pull/1705\nhttps://github.com/libssh2/libssh2/pull/1717\nhttps://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d\nhttps://www.vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c",
    "id": "CVE-2025-15661",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125"
    ],
    "cvelist": null,
    "sourceData": "libssh2 libssh2 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.3,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
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            "privilegesRequired": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "libssh2",
    "version": "0",
    "vendor": "libssh2",
    "ai_description": "",
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    "ai_vendor": "",
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    "ai_score": 0
}