GHSA-4MRH-9QQ5-26W5
Vulnerability from github – Published: 2026-03-25 12:30 – Updated: 2026-07-14 15:31In the Linux kernel, the following vulnerability has been resolved:
net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. If an IPv6 packet is injected into the interface, route_shortcircuit() is called and a NULL pointer dereference happens on neigh_lookup().
BUG: kernel NULL pointer dereference, address: 0000000000000380 Oops: Oops: 0000 [#1] SMP NOPTI [...] RIP: 0010:neigh_lookup+0x20/0x270 [...] Call Trace: vxlan_xmit+0x638/0x1ef0 [vxlan] dev_hard_start_xmit+0x9e/0x2e0 __dev_queue_xmit+0xbee/0x14e0 packet_sendmsg+0x116f/0x1930 __sys_sendto+0x1f5/0x200 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x12f/0x1590 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by adding an early check on route_shortcircuit() when protocol is ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here because VXLAN can be built-in even when IPv6 is built as a module.
{
"affected": [],
"aliases": [
"CVE-2026-23293"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-25T11:16:24Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled\n\nWhen booting with the \u0027ipv6.disable=1\u0027 parameter, the nd_tbl is never\ninitialized because inet6_init() exits before ndisc_init() is called\nwhich initializes it. If an IPv6 packet is injected into the interface,\nroute_shortcircuit() is called and a NULL pointer dereference happens on\nneigh_lookup().\n\n BUG: kernel NULL pointer dereference, address: 0000000000000380\n Oops: Oops: 0000 [#1] SMP NOPTI\n [...]\n RIP: 0010:neigh_lookup+0x20/0x270\n [...]\n Call Trace:\n \u003cTASK\u003e\n vxlan_xmit+0x638/0x1ef0 [vxlan]\n dev_hard_start_xmit+0x9e/0x2e0\n __dev_queue_xmit+0xbee/0x14e0\n packet_sendmsg+0x116f/0x1930\n __sys_sendto+0x1f5/0x200\n __x64_sys_sendto+0x24/0x30\n do_syscall_64+0x12f/0x1590\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nFix this by adding an early check on route_shortcircuit() when protocol\nis ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here because\nVXLAN can be built-in even when IPv6 is built as a module.",
"id": "GHSA-4mrh-9qq5-26w5",
"modified": "2026-07-14T15:31:40Z",
"published": "2026-03-25T12:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23293"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/168ff39e4758897d2eee4756977d036d52884c7e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5f93e6b4d12bd3a4517a6d447ea675f448f21434"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/649e2bb74da54c96cf20729001e283626a2fefa0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/abcd48ecdeb2e12eccb8339a35534c757782afcd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b5190fcd75a1f1785c766a8d1e44d3938e168f45"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc3e62cf3bbf66280a907ec379f373d0c3b8b2bc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f0373e9317bc904e7bdb123d3106fe4f3cea2fb7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fbbd2118982c55fb9b0a753ae0cf7194e77149fb"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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