{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63864",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.017Z",
        "datePublished": "2026-07-19T14:04:50.605Z",
        "dateUpdated": "2026-08-05T12:36:40.261Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:36:40.261Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Propagate error from visit_tailcall_insn\n\nCommit e40f5a6bf88a (\"bpf: correct stack liveness for tail calls\") added\nvisit_tailcall_insn() but did not check its return value."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 8.4,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The bug is reached only through the bpf() syscall during BPF_PROG_LOAD verification (check_cfg/visit_insn), which is a local kernel interface per kernel CVSS guidance for BPF.\nAC:L - An attacker can craft a BPF program using tail calls and subprograms to hit visit_tailcall_insn(), and can pressure kernel memory (parallel BPF loads/maps) to make the small jt allocation fail while verification continues.\nPR:N - Exploitation occurs at BPF_PROG_LOAD time via bpf(); on systems with kernel.unprivileged_bpf_disabled=0, unprivileged users can load socket-filter programs with PROG_ARRAY maps and tail calls without CAP_BPF or root.\nUI:N - No victim interaction is required; the attacker triggers the flaw by loading a malicious BPF program through their own bpf() syscall.\nS:U - Impact is a BPF verifier bypass leading to kernel memory corruption and local privilege escalation within the same kernel security boundary, not a cross-authority escape such as VM guest-to-host.\nC:H - Incorrect tail-call stack liveness lets verifier-approved programs perform out-of-bounds stack reads at runtime, exposing adjacent kernel stack memory and enabling arbitrary kernel memory disclosure primitives.\nI:H - The verifier bypass permits out-of-bounds stack writes and type confusion on stack slots, which can be leveraged for control-flow hijacking and arbitrary kernel code execution from BPF context.\nA:H - Out-of-bounds BPF stack access can trigger kernel oops/panic during program execution, and repeated exploitation can be used for denial of service even when full exploitation is not attempted."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/verifier.c"
                    ],
                    "versions": [
                        {
                            "version": "e40f5a6bf88a781d5f81bc6b8aab9ac31d8c98dd",
                            "lessThan": "945816e63c8677cf4bfde963a0774432ce8afc85",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e40f5a6bf88a781d5f81bc6b8aab9ac31d8c98dd",
                            "lessThan": "6bd96e40f31dde8f8cd79772b4df0f171cf8a915",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/verifier.c"
                    ],
                    "versions": [
                        {
                            "version": "6.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.10",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "6.19",
                                    "versionEndExcluding": "7.0.10"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.19",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/945816e63c8677cf4bfde963a0774432ce8afc85"
                },
                {
                    "url": "https://git.kernel.org/stable/c/6bd96e40f31dde8f8cd79772b4df0f171cf8a915"
                }
            ],
            "title": "bpf: Propagate error from visit_tailcall_insn",
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                "engine": "bippy-1.2.0"
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        }
    }
}