{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43070",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-01T14:12:55.982Z",
        "datePublished": "2026-05-05T15:23:28.819Z",
        "dateUpdated": "2026-08-05T12:25:43.557Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:25:43.557Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reset register ID for BPF_END value tracking\n\nWhen a register undergoes a BPF_END (byte swap) operation, its scalar\nvalue is mutated in-place. If this register previously shared a scalar ID\nwith another register (e.g., after an `r1 = r0` assignment), this tie must\nbe broken.\n\nCurrently, the verifier misses resetting `dst_reg->id` to 0 for BPF_END.\nConsequently, if a conditional jump checks the swapped register, the\nverifier incorrectly propagates the learned bounds to the linked register,\nleading to false confidence in the linked register's value and potentially\nallowing out-of-bounds memory accesses.\n\nFix this by explicitly resetting `dst_reg->id` to 0 in the BPF_END case\nto break the scalar tie, similar to how BPF_NEG handles it via\n`__mark_reg_known`."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable verifier logic is reached by a local attacker through the bpf() syscall when loading an eBPF program, not by remote packets directly.\nAC:L - The attacker controls the BPF bytecode and can construct the shared scalar-ID plus BPF_END pattern; there is no race or external timing condition required beyond program execution.\nPR:L - A basic local user can reach this in deployments with unprivileged BPF enabled or delegated BPF token capability; if uncertain between requiring CAP_BPF and unprivileged reachability, the higher-severity PR:L is appropriate.\nUI:N - No victim action is required; the attacker loads and triggers the BPF program themselves.\nS:U - The impact is within the kernel security authority, matching a standard local kernel privilege escalation rather than a cross-scope escape.\nC:H - The verifier can incorrectly validate out-of-bounds memory accesses, and such memory corruption/read primitives can expose arbitrary kernel memory.\nI:H - The demonstrated bad bounds propagation permits out-of-bounds writes through BPF pointer arithmetic, which is defensibly exploitable for kernel memory corruption or code execution.\nA:H - Out-of-bounds kernel memory access can crash or panic the kernel even if not fully exploited."
                        }
                    ]
                }
            ],
            "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": "4c03342e5ac532fb34d13a7b51dd7261dfc48963",
                            "lessThan": "a17443af874229408ce6b78e2c8a2b5adeb4b7d8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "d00ce96623a69a100ad79675d0e85fda3c50d89b",
                            "lessThan": "0d15c3611a2cc5d08993545d4032055ae10ae2c1",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9d21199842247ab05c675fb9b6c6ca393a5c0024",
                            "lessThan": "a3125bc01884431d30d731461634c8295b6f0529",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "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": "6.18.17",
                            "lessThan": "6.18.21",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.7",
                            "lessThan": "6.19.11",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.18.17",
                                    "versionEndExcluding": "6.18.21"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.19.7",
                                    "versionEndExcluding": "6.19.11"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a17443af874229408ce6b78e2c8a2b5adeb4b7d8"
                },
                {
                    "url": "https://git.kernel.org/stable/c/0d15c3611a2cc5d08993545d4032055ae10ae2c1"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a3125bc01884431d30d731461634c8295b6f0529"
                }
            ],
            "title": "bpf: Reset register ID for BPF_END value tracking",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}