CVE-2026-74258 (GCVE-0-2026-74258)
Vulnerability from cvelistv5
Published
2026-08-15 05:57
Modified
2026-08-17 05:45
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
bpf: Guard __get_user acesss with access_ok for uprobe_multi data
As reported by sashiko [1] we need to use access_ok to check the user
space data bounds before we use __get-user to get it.
[1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"kernel/trace/bpf_trace.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c6d51ad36490013ee9df94a372d3bf794bd304d1",
"status": "affected",
"version": "89ae89f53d201143560f1e9ed4bfa62eee34f88e",
"versionType": "git"
},
{
"lessThan": "4d87a251d45b4a95eb4c0abcfab809c9f231258a",
"status": "affected",
"version": "89ae89f53d201143560f1e9ed4bfa62eee34f88e",
"versionType": "git"
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"lessThan": "6.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Guard __get_user acesss with access_ok for uprobe_multi data\n\nAs reported by sashiko [1] we need to use access_ok to check the user\nspace data bounds before we use __get-user to get it.\n\n[1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is in bpf_uprobe_multi_link_attach(), reached only via the local bpf(BPF_LINK_CREATE) syscall with BPF_TRACE_UPROBE_MULTI; per kernel CNA guidance BPF/uprobe link creation is Local, not network-reachable.\nAC:L - The attacker fully controls link_create.uprobe_multi offsets/ref_ctr_offsets/cookies pointers and cnt, so __get_user runs on attacker-chosen addresses without races or external conditions; repeated attempts reliably leak or fault.\nPR:L - Exploitation requires a BPF_PROG_TYPE_KPROBE program (CAP_BPF+CAP_PERFMON), routinely delegated via BPF tokens into non-init user namespaces for tracing/container workloads; this is low privilege, not init-namespace root.\nUI:N - No victim interaction is needed; the attacker loads the BPF program, issues BPF_LINK_CREATE with crafted pointers, and can read leaked data back via BPF_OBJ_GET_INFO_BY_FD on their own link.\nS:U - Impact is arbitrary kernel memory disclosure and possible host compromise within the same kernel security authority; it does not cross VM, IOMMU, or container sandbox boundaries by itself.\nC:H - Missing access_ok lets __get_user copy from kernel addresses into uprobes arrays (up to cnt*8 bytes); cookies/offsets can be exfiltrated through bpf_uprobe_multi_link_fill_link_info, giving arbitrary kernel memory read.\nI:H - Leaked kernel pointers and attacker-influenced offset/ref_ctr values feed uprobe_register() breakpoint installation, and the read primitive is standardly chained into arbitrary kernel write and privilege escalation.\nA:H - __get_user on non-userspace addresses can fault under SMAP/PAN and oops the kernel; even failed exploitation attempts can crash the host, and guidance treats serious uaccess bugs as high availability impact."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:45:07.606Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
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"references": [
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"url": "https://git.kernel.org/stable/c/c6d51ad36490013ee9df94a372d3bf794bd304d1"
},
{
"url": "https://git.kernel.org/stable/c/4d87a251d45b4a95eb4c0abcfab809c9f231258a"
}
],
"title": "bpf: Guard __get_user acesss with access_ok for uprobe_multi data",
"x_generator": {
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74258",
"datePublished": "2026-08-15T05:57:36.257Z",
"dateReserved": "2026-08-15T05:44:03.877Z",
"dateUpdated": "2026-08-17T05:45:07.606Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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