CVE-2026-99211 (GCVE-0-2026-99211)
Vulnerability from cvelistv5
Published
2026-10-28 10:36
Modified
2026-10-28 10:36
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
netlink: reset skb headers before unicast and multicast filtering
Socket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to
an skb's network and MAC headers. Netlink producers may reserve
headroom without resetting those headers, allowing a receiving socket's
filter to read data before the initialized message.
For example, IWPM HELLO replies are allocated with dev_alloc_skb(),
which reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can
attach a classic socket filter and disclose this headroom through the
length of the delivered reply. The resets in netlink_dump() do not help
because IWPM sends a separately allocated skb through netlink_unicast().
Reset both headers before running the receiver's filter in unicast and
broadcast delivery, as is already done for dump skbs. This also covers
other netlink producers that reserve headroom without changing their
allocation or message-building code.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/netlink/af_netlink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "06791594274f87c29f1a9f1961d700272716a49d",
"status": "affected",
"version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
"versionType": "git"
},
{
"lessThan": "06935da5de83aa8b98841563894857e7d2f80e47",
"status": "affected",
"version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
"versionType": "git"
},
{
"lessThan": "8bf659bd54e1f00e34cf5244b1d289c506fa47c0",
"status": "affected",
"version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/netlink/af_netlink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.26"
},
{
"lessThan": "2.6.26",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.59",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.59",
"versionStartIncluding": "2.6.26",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.13",
"versionStartIncluding": "2.6.26",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "2.6.26",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetlink: reset skb headers before unicast and multicast filtering\n\nSocket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to\nan skb\u0027s network and MAC headers. Netlink producers may reserve\nheadroom without resetting those headers, allowing a receiving socket\u0027s\nfilter to read data before the initialized message.\n\nFor example, IWPM HELLO replies are allocated with dev_alloc_skb(),\nwhich reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can\nattach a classic socket filter and disclose this headroom through the\nlength of the delivered reply. The resets in netlink_dump() do not help\nbecause IWPM sends a separately allocated skb through netlink_unicast().\n\nReset both headers before running the receiver\u0027s filter in unicast and\nbroadcast delivery, as is already done for dump skbs. This also covers\nother netlink producers that reserve headroom without changing their\nallocation or message-building code."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-28T10:36:04.864Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/06791594274f87c29f1a9f1961d700272716a49d"
},
{
"url": "https://git.kernel.org/stable/c/06935da5de83aa8b98841563894857e7d2f80e47"
},
{
"url": "https://git.kernel.org/stable/c/8bf659bd54e1f00e34cf5244b1d289c506fa47c0"
}
],
"title": "netlink: reset skb headers before unicast and multicast filtering",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-99211",
"datePublished": "2026-10-28T10:36:04.864Z",
"dateReserved": "2026-09-25T10:25:14.401Z",
"dateUpdated": "2026-10-28T10:36:04.864Z",
"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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