netfilter: xt_tcpmss: check remaining length before reading optlen_CVE-2026-43190

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_tcpmss: check remaining length before reading optlen\n\nQuoting reporter:\n  In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads\n op[i+1] directly without validating the remaining option length.\n\n  If the last byte of the option field is not EOL/NOP (0/1), the code attempts\n  to index op[i+1]. In the case where i + 1 == optlen, this causes an\n  out-of-bounds read, accessing memory past the optlen boundary\n  (either reading beyond the stack buffer _opt or the\n  following payload).",
    "published": "2026-05-06T11:27:59.798Z",
    "modified": "2026-05-08T12:41:06.952Z",
    "type": "cve",
    "title": "netfilter: xt_tcpmss: check remaining length before reading optlen",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287\nhttps://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885\nhttps://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824\nhttps://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3\nhttps://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e\nhttps://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05\nhttps://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09\nhttps://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3",
    "id": "CVE-2026-43190",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\nLinux Linux 2.6.12",
    "sourceHref": "",
    "cvss": {
        "score": 8.2,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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": "Linux",
    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}