CVE-2026-74695
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref() Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dst_entry assigned during earlier RX or routing steps. Calling skb_dst_set_noref() when skb already holds a ref-counted dst overwrites skb->_skb_refdst, leaking the previous dst_entry reference count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in skb_dst_check_unset(): WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170 WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234 WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864 Drop any existing dst_entry reference with skb_dst_drop(skb) before setting the non-referenced flowtable destination.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-22 16:16:44.050000
Last modified
2026-10-30 13:20:04.100000
View original CVE JSON
{
"id": "CVE-2026-74695",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-22T16:16:44.050",
"lastModified": "2026-10-30T13:20:04.100",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()\n\nIncoming skbs passing through netfilter flowtable offload hooks (or XFRM\noffload path) might already carry a ref-counted dst_entry assigned during\nearlier RX or routing steps.\n\nCalling skb_dst_set_noref() when skb already holds a ref-counted dst\noverwrites skb->_skb_refdst, leaking the previous dst_entry reference\ncount and triggering a DEBUG_NET_WARN_ON_ONCE assertion in\nskb_dst_check_unset():\n\n WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170\n WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234\n WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864\n\nDrop any existing dst_entry reference with skb_dst_drop(skb) before\nsetting the non-referenced flowtable destination."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnetfilter: nf_flow_table: descartar el dst de skb existente antes de skb_dst_set_noref()\n\nLos skbs entrantes que pasan por los hooks de descarga de la tabla de flujos de netfilter (o la ruta de descarga de XFRM) podrían ya llevar un dst_entry con contador de referencias asignado durante pasos anteriores de RX o enrutamiento.\n\nLlamar a skb_dst_set_noref() cuando el skb ya contiene un dst con contador de referencias sobrescribe skb -> _skb_refdst, filtrando el contador de referencias del dst_entry anterior y disparando una aserción DEBUG_NET_WARN_ON_ONCE en skb_dst_check_unset():\n\n ADVERTENCIA: en skb_dst_check_unset include/linux/skbuff.h:1170\n ADVERTENCIA: en skb_dst_set_noref include/linux/skbuff.h:1234\n ADVERTENCIA: en nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864\n\nDescartar cualquier referencia de dst_entry existente con skb_dst_drop(skb) antes de establecer el destino de la tabla de flujos sin referencias."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/netfilter/nf_flow_table_ip.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "2a79fd3908acd88e6cb0e620c314d7b1fee56a02",
"lessThan": "763f59b72ddaf18d0750d53083a74355f6c003c8",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "4db3b48a966ed479b99cc8319ea9e46d4f7c703b",
"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"
},
{
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"lessThan": "8aecf0bbcc72605592134c917c222207d8f63ab0",
"versionType": "git",
"status": "affected"
},
{
"version": "b4b1adf2e66ecc7125c4117e7aad9ff61e2cfd27",
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"status": "affected"
},
{
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"status": "affected"
},
{
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"lessThan": "4.17",
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},
{
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}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/netfilter/nf_flow_table_ip.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
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"status": "affected"
},
{
"version": "0",
"lessThan": "4.18",
"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": "6.12.114",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.45",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.9",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T19:14:42.839344Z",
"id": "CVE-2026-74695",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
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"url": "https://git.kernel.org/stable/c/12afa450a6a6c0cce2c42b7545a9958f62d8a00c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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{
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]
}