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vuln-cve/data/2026/72xxx/CVE-2026-72426.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-72426",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-08-09T03:40:39.928Z",
"datePublished": "2026-08-15T05:56:43.575Z",
"dateUpdated": "2026-08-17T05:44:06.105Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-08-17T05:44:06.105Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve pointer spill metadata during half-slot cleanup\n\n__clean_func_state() cleans dead stack slots in 4-byte halves. When the\nhigh half of a STACK_SPILL slot is dead and the low half remains live,\ncleanup converts the live low half to STACK_MISC or STACK_ZERO and clears\nthe saved spilled_ptr metadata.\n\nThat conversion is safe only for scalar spills. For a pointer spill, this\nmetadata clear lets a later 32-bit fill from the still-live half avoid the\nnormal non-scalar register-fill check and be treated as an ordinary scalar\nstack read.\n\nLeave non-scalar spill slots intact in this half-live shape. This is\nconservative for pruning and preserves the existing\ncheck_stack_read_fixed_off() rejection path for partial fills from pointer\nspills."
}
],
"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 flaw is reached only through the local bpf(BPF_PROG_LOAD) syscall during BPF verifier state pruning in bpf_is_state_visited()->clean_verifier_state()->__clean_func_state(), which is a local kernel interface per BPF CVSS guidance.\nAC:L - An attacker fully controls the crafted BPF bytecode, can spill a pointer, force verifier checkpoints (e.g., BPF_F_TEST_STATE_FREQ or branch pruning), and reliably trigger the half-slot cleanup path without races or external timing.\nPR:N - Exploitation occurs at BPF_PROG_LOAD via bpf(); on systems with kernel.unprivileged_bpf_disabled=0, unprivileged users can load socket-filter programs that trigger this verifier path without CAP_BPF or init-namespace root.\nUI:N - No victim interaction is required; the attacker loads and verifies their own malicious BPF program through the 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 - Cleared pointer spill metadata lets partial 32-bit fills bypass non-scalar register-fill checks, causing verifier/runtime type confusion that can be developed into arbitrary kernel memory disclosure primitives.\nI:H - Verifier-approved programs can treat pointer spill bytes as scalars and perform unsafe memory operations, enabling out-of-bounds writes and control-flow hijacking for arbitrary kernel code execution from BPF context.\nA:H - Executing verifier-incorrect BPF with confused pointer/scalar state can trigger kernel oops or panic, and the attacker can repeatedly load and run crafted programs to cause denial of service."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/bpf/states.c"
],
"versions": [
{
"version": "be23266b4a08540aa43d8503a2ea10247c8daebe",
"lessThan": "0f9278b22cda6fd2525049930157b79b4036b4ef",
"status": "affected",
"versionType": "git"
},
{
"version": "be23266b4a08540aa43d8503a2ea10247c8daebe",
"lessThan": "3a354149bceacadbcf7d7b4766f5ef26a85892ab",
"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/states.c"
],
"versions": [
{
"version": "7.1",
"status": "affected"
},
{
"version": "0",
"lessThan": "7.1",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.1.5",
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.2",
"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": "7.1",
"versionEndExcluding": "7.1.5"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "7.1",
"versionEndExcluding": "7.2"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/0f9278b22cda6fd2525049930157b79b4036b4ef"
},
{
"url": "https://git.kernel.org/stable/c/3a354149bceacadbcf7d7b4766f5ef26a85892ab"
}
],
"title": "bpf: Preserve pointer spill metadata during half-slot cleanup",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
}
}