CVE-2026-63917
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ip6: vti: Use ip6_tnl.net in vti6_changelink(). ip netns add ns1 ip netns add ns2 ip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7 ip -n ns1 link set vti6_test netns ns2 ip -n ns2 link set vti6_test type vti6 remote ::3 local ::4 key 9 ip netns del ns2 ip netns del ns1 [ 132.495484] ------------[ cut here ]------------ [ 132.497609] kernel BUG at net/core/dev.c:12376! Commit 61220ab34948 ("vti6: Enable namespace changing") dropped NETIF_F_NETNS_LOCAL from vti6 devices. A vti6 tunnel can then move through IFLA_NET_NS_FD. After the move dev_net(dev) points at the new netns while t->net stays at the creation netns. vti6_changelink() and vti6_update() still use dev_net(dev) and dev_net(t->dev). They unlink from one per netns hash and relink into another. The creation netns is left with a stale entry. cleanup_net() of that netns later walks freed memory. Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). Cross tenant scope on container hosts.
Severity
HIGH
CVSS score
8.8
(v3.1)
Vulnerability status
Undergoing Analysis
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:17:09.783000
Last modified
2026-10-19 21:17:10.923000
View original CVE JSON
{
"id": "CVE-2026-63917",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-19T16:17:09.783",
"lastModified": "2026-10-19T21:17:10.923",
"vulnStatus": "Undergoing Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6: vti: Use ip6_tnl.net in vti6_changelink().\n\nip netns add ns1\nip netns add ns2\nip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7\nip -n ns1 link set vti6_test netns ns2\nip -n ns2 link set vti6_test type vti6 remote ::3 local ::4 key 9\nip netns del ns2\nip netns del ns1\n[ 132.495484] ------------[ cut here ]------------\n[ 132.497609] kernel BUG at net/core/dev.c:12376!\n\nCommit 61220ab34948 (\"vti6: Enable namespace changing\") dropped\nNETIF_F_NETNS_LOCAL from vti6 devices. A vti6 tunnel can then\nmove through IFLA_NET_NS_FD. After the move dev_net(dev) points\nat the new netns while t->net stays at the creation netns.\n\nvti6_changelink() and vti6_update() still use dev_net(dev) and\ndev_net(t->dev). They unlink from one per netns hash and relink\ninto another. The creation netns is left with a stale entry.\ncleanup_net() of that netns later walks freed memory.\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net). Cross tenant scope on container hosts."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ipv6/ip6_vti.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "61220ab349485d911083d0b7990ccd3db6c63297",
"lessThan": "0cdce7618464f7fb06f461e8f4ad575cb1d570f4",
"versionType": "git",
"status": "affected"
},
{
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"status": "affected"
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"status": "affected"
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{
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"versionType": "git",
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{
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"versionType": "git",
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},
{
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}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/ipv6/ip6_vti.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.15",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.15",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.259",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.210",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.176",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.143",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.93",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.35",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.0.12",
"lessThanOrEqual": "7.0.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1",
"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:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.0,
"impactScore": 6.0
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:33:18.521375Z",
"id": "CVE-2026-63917",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/0cdce7618464f7fb06f461e8f4ad575cb1d570f4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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{
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]
}