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vuln-cve/data/2026/72xxx/CVE-2026-72042.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-72042",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-08-09T03:40:39.902Z",
"datePublished": "2026-08-15T05:52:01.454Z",
"dateUpdated": "2026-08-17T05:39:41.572Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-08-17T05:39:41.572Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipmi: Fix user refcount underflow in event delivery\n\nipmi_alloc_recv_msg(user) takes the temporary user reference owned by the\nreceive message, and ipmi_free_recv_msg() drops it again. If event delivery\nfails after allocating receive messages for earlier users,\nhandle_read_event_rsp() rolls those messages back with\nipmi_free_recv_msg().\n\nThat rollback path still drops user->refcount explicitly after freeing each\nmessage. The extra put can free a user that remains linked on intf->users,\nso later event delivery may dereference a freed user or trip refcount_t's\naddition-on-zero warning when ipmi_alloc_recv_msg() tries to acquire\nanother reference.\n\nRemove the stale explicit put and the now-dead user assignment. Keep the\nlist_del() and ipmi_free_recv_msg() calls; they are the required rollback\noperations."
}
],
"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 - Exploitation requires local setup via /dev/ipmiN (open, IPMICTL_SET_GETS_EVENTS, message flooding); the refcount bug is in handle_read_event_rsp() during host-side BMC event processing, not via a remote packet path to the kernel.\nAC:L - An attacker with IPMI device access controls both sides: multiple fds, gets_events registration, filling one user's outstanding-message limit to force EBUSY, and generating/waiting for BMC events via their own IPMI commands.\nPR:L - ipmi_open/ipmi_create_user perform no capability() check; access is gated only by /dev/ipmiN DAC, and BMC-equipped servers often grant that node to a non-root management group (ipmi) for ipmitool/freeipmi.\nUI:N - No victim interaction is required; the attacker drives all setup and triggering through their own IPMI file descriptors and ioctls.\nS:U - This is a host-kernel heap use-after-free of struct ipmi_user within the same OS security authority, with no VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - Premature free_ipmi_user() leaves a dangling ipmi_user on intf->users; later iterations call kref_get and read handler pointers from freed slab memory, yielding arbitrary kernel read primitives per UAF guidance.\nI:H - Freed ipmi_user objects contain function pointers (handler->ipmi_recv_hndl); smi_work later invokes these on reclaimed memory, enabling heap spray and control-flow hijack for arbitrary kernel write/code execution.\nA:H - The extra kref_put causes refcount underflow warnings and use-after-free of ipmi_user; subsequent event delivery dereferences freed memory and readily triggers kernel oops/panic under KASAN/poisoning."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/char/ipmi/ipmi_msghandler.c"
],
"versions": [
{
"version": "b52da4054ee0bf9ecb44996f2c83236ff50b3812",
"lessThan": "ddbb6e3dc9bb4743de686aa1598c31e745cee76b",
"status": "affected",
"versionType": "git"
},
{
"version": "b52da4054ee0bf9ecb44996f2c83236ff50b3812",
"lessThan": "7be349d4fcc5e065295b83418a22d27a68afbdb6",
"status": "affected",
"versionType": "git"
},
{
"version": "b52da4054ee0bf9ecb44996f2c83236ff50b3812",
"lessThan": "6aa9e61c46465d231e9beddf56af7effd71be682",
"status": "affected",
"versionType": "git"
},
{
"version": "f63723ca7d7623f9dae1990973cd158671f03c56",
"status": "affected",
"versionType": "git"
},
{
"version": "348121b29594d42d1635648fd3ed31dfa25351d5",
"status": "affected",
"versionType": "git"
},
{
"version": "53d6e403affbf6df2c859a0ea00ccfc1e72090ca",
"status": "affected",
"versionType": "git"
},
{
"version": "0ed73be9a2547ffb9b5c1d879ad9bfab73d920b5",
"status": "affected",
"versionType": "git"
},
{
"version": "6.1.157",
"lessThan": "6.2",
"status": "affected",
"versionType": "semver"
},
{
"version": "6.6.113",
"lessThan": "6.7",
"status": "affected",
"versionType": "semver"
},
{
"version": "6.12.54",
"lessThan": "6.13",
"status": "affected",
"versionType": "semver"
},
{
"version": "6.17.4",
"lessThan": "6.18",
"status": "affected",
"versionType": "semver"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/char/ipmi/ipmi_msghandler.c"
],
"versions": [
{
"version": "6.18",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.18",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.18.40",
"lessThanOrEqual": "6.18.*",
"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": "6.18",
"versionEndExcluding": "6.18.40"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.18",
"versionEndExcluding": "7.1.5"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.18",
"versionEndExcluding": "7.2"
},
{
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"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.1.157"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.6.113"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.12.54"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.17.4"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/ddbb6e3dc9bb4743de686aa1598c31e745cee76b"
},
{
"url": "https://git.kernel.org/stable/c/7be349d4fcc5e065295b83418a22d27a68afbdb6"
},
{
"url": "https://git.kernel.org/stable/c/6aa9e61c46465d231e9beddf56af7effd71be682"
}
],
"title": "ipmi: Fix user refcount underflow in event delivery",
"x_generator": {
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}