CVE-2026-99072
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: stop route notification sizing when nexthop group shrinks Commit 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") added an RCU-only fib_nlmsg_size() call for asynchronous hardware flag notifications. fib_nlmsg_size() checks fib_info_num_path() before each iteration, then fib_info_nhc() independently reloads nh->nh_grp. If RTM_NEWNEXTHOP replaces a group with fewer paths between those loads, fib_info_nhc() returns NULL and fib_nexthop_nlmsg_size() dereferences it. Stop sizing when the indexed path is absent. Nexthop groups are dense, so the current snapshot has no later path.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-23 13:17:31.143000
Last modified
2026-10-30 13:21:43.523000
View original CVE JSON
{
"id": "CVE-2026-99072",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-23T13:17:31.143",
"lastModified": "2026-10-30T13:21:43.523",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: stop route notification sizing when nexthop group shrinks\n\nCommit 680aea08e78c (\"net: ipv4: Emit notification when fib\nhardware flags are changed\") added an RCU-only fib_nlmsg_size() call\nfor asynchronous hardware flag notifications.\n\nfib_nlmsg_size() checks fib_info_num_path() before each iteration,\nthen fib_info_nhc() independently reloads nh->nh_grp. If\nRTM_NEWNEXTHOP replaces a group with fewer paths between those loads,\nfib_info_nhc() returns NULL and fib_nexthop_nlmsg_size() dereferences\nit.\n\nStop sizing when the indexed path is absent. Nexthop groups are\ndense, so the current snapshot has no later path."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ipv4/fib_semantics.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "680aea08e78c003292415518ad270bc20f9c80b1",
"lessThan": "96f3fbb8575593657c7e80786dc3251d2fe3931b",
"versionType": "git",
"status": "affected"
},
{
"version": "680aea08e78c003292415518ad270bc20f9c80b1",
"lessThan": "81f0deb02a5b5477f236bbbaed1149b779a8632b",
"versionType": "git",
"status": "affected"
},
{
"version": "680aea08e78c003292415518ad270bc20f9c80b1",
"lessThan": "72d9d17092bb37b0717f12042a0817d01a1f9e78",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "ad1c9f1b98c92609e9bb2ae8f05916defc3b0a54",
"versionType": "git",
"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
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{
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"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/ipv4/fib_semantics.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.224",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.113",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.11",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/72d9d17092bb37b0717f12042a0817d01a1f9e78",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/81f0deb02a5b5477f236bbbaed1149b779a8632b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/96f3fbb8575593657c7e80786dc3251d2fe3931b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ad1c9f1b98c92609e9bb2ae8f05916defc3b0a54",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ad2b3a68b8a7d5d27de88e05674e4adb1ce46d88",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c1f48d1c2d5e9efd904dbbc2f2b3d41543e55c49",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d3daa33c7af92e38f2274bbd2576f58bfbaf89e6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}