{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43384",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-01T14:12:56.006Z",
        "datePublished": "2026-05-08T14:21:31.355Z",
        "dateUpdated": "2026-08-05T12:27:42.918Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:27:42.918Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-ao: Fix MAC comparison to be constant-time\n\nTo prevent timing attacks, MACs need to be compared in constant\ntime.  Use the appropriate helper function for this."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 9.8,
                        "baseSeverity": "CRITICAL"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The vulnerable comparison is reached by inbound IPv4/IPv6 TCP packets carrying a TCP-AO option, before normal TCP processing of the segment.\nAC:L - The attacker controls the candidate MAC bytes and can send repeated chosen packets to average timing differences; no race or condition outside the attacker’s control is required once a TCP-AO-protected socket is reachable.\nPR:N - The vulnerable path is the TCP-AO authentication check itself, so the attacker does not need the AO key or any local privilege before sending probes.\nUI:N - No victim user action is required; packet receipt by the configured TCP-AO endpoint is sufficient.\nS:U - The impact remains within the kernel/network endpoint and the TCP sessions protected by that endpoint, with no VM, sandbox, or separate security-authority escape.\nC:H - A successful MAC-forgery timing attack can let an unauthenticated network attacker impersonate a trusted TCP-AO peer and receive data made available to that authenticated peer.\nI:H - Forged valid TCP-AO segments can inject or alter arbitrary TCP stream/control data for protected connections, defeating the integrity guarantee TCP-AO is meant to provide.\nA:H - Forged valid TCP-AO control segments such as RST/FIN or malicious stream data can tear down or disrupt protected long-lived sessions such as routing/control-plane connections."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/Kconfig",
                        "net/ipv4/tcp_ao.c"
                    ],
                    "versions": [
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "8be6ed64966da48b6c4726918f106c18742a5125",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "a269cbdc442f8658bca35383e34b9d0b0ff95a1c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "080b0e210088296dd50d6637c06c1db14246adfe",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "67edfec516d30d3e62925c397be4a1e5185802fc",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/Kconfig",
                        "net/ipv4/tcp_ao.c"
                    ],
                    "versions": [
                        {
                            "version": "6.7",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.7",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.78",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.19",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.9",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.12.78"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.18.19"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.19.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
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                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/8be6ed64966da48b6c4726918f106c18742a5125"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a269cbdc442f8658bca35383e34b9d0b0ff95a1c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/080b0e210088296dd50d6637c06c1db14246adfe"
                },
                {
                    "url": "https://git.kernel.org/stable/c/67edfec516d30d3e62925c397be4a1e5185802fc"
                }
            ],
            "title": "net/tcp-ao: Fix MAC comparison to be constant-time",
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}