CVE-2026-97965
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: vxlan: initialize _md in vxlan_xmit_one() If a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and VXLAN_F_GBP, and a packet is transmitted through it using an external ip_tunnel_info that lacks the IP_TUNNEL_VXLAN_OPT_BIT flag, md is left pointing to the uninitialized _md stack variable: if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) { if (info->options_len < sizeof(*md)) goto drop; md = ip_tunnel_info_opts(info); } Because IP_TUNNEL_VXLAN_OPT_BIT is not set, md is not updated and remains pointing to _md. Later, vxlan_build_skb() is called with md, which eventually calls vxlan_build_gbp_hdr(): if (vxflags & VXLAN_F_GBP) vxlan_build_gbp_hdr(vxh, md); Inside vxlan_build_gbp_hdr(), md->gbp is read: if (!md->gbp) return; gbp = (struct vxlanhdr_gbp *)vxh; ... if (md->gbp & VXLAN_GBP_DONT_LEARN) gbp->dont_learn = 1; If the stack contains garbage, this causes: 1) VXLAN_HF_GBP flag to be spuriously set in the VXLAN header. 2) gbp->dont_learn and gbp->policy_applied to be set from stack bits. 3) gbp->policy_id to receive 16 bits of uninitialized kernel stack data, leaking it onto the wire. Fix this by zero-initializing _md. If IP_TUNNEL_VXLAN_OPT_BIT is not present, md->gbp remains 0, and vxlan_build_gbp_hdr() returns early without modifying the VXLAN header.
View original CVE JSON
{
"id": "CVE-2026-97965",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-25T11:17:24.293",
"lastModified": "2026-10-21T13:21:17.963",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: initialize _md in vxlan_xmit_one()\n\nIf a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and\nVXLAN_F_GBP, and a packet is transmitted through it using an external\nip_tunnel_info that lacks the IP_TUNNEL_VXLAN_OPT_BIT flag, md is left\npointing to the uninitialized _md stack variable:\n\n if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) {\n if (info->options_len < sizeof(*md))\n goto drop;\n md = ip_tunnel_info_opts(info);\n }\n\nBecause IP_TUNNEL_VXLAN_OPT_BIT is not set, md is not updated and remains\npointing to _md. Later, vxlan_build_skb() is called with md, which\neventually calls vxlan_build_gbp_hdr():\n\n if (vxflags & VXLAN_F_GBP)\n vxlan_build_gbp_hdr(vxh, md);\n\nInside vxlan_build_gbp_hdr(), md->gbp is read:\n\n if (!md->gbp)\n return;\n gbp = (struct vxlanhdr_gbp *)vxh;\n ...\n if (md->gbp & VXLAN_GBP_DONT_LEARN)\n gbp->dont_learn = 1;\n\nIf the stack contains garbage, this causes:\n1) VXLAN_HF_GBP flag to be spuriously set in the VXLAN header.\n2) gbp->dont_learn and gbp->policy_applied to be set from stack bits.\n3) gbp->policy_id to receive 16 bits of uninitialized kernel stack data,\n leaking it onto the wire.\n\nFix this by zero-initializing _md. If IP_TUNNEL_VXLAN_OPT_BIT is not\npresent, md->gbp remains 0, and vxlan_build_gbp_hdr() returns early\nwithout modifying the VXLAN header."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "ee122c79d4227f6ec642157834b6a90fcffa4382",
"lessThan": "fb78beb64e0e79557e4cd7cd17fea744bb6f01d9",
"versionType": "git",
"status": "affected"
},
{
"version": "ee122c79d4227f6ec642157834b6a90fcffa4382",
"lessThan": "0d13b5a413bffc8718b3821b78537ccc6596c233",
"versionType": "git",
"status": "affected"
},
{
"version": "ee122c79d4227f6ec642157834b6a90fcffa4382",
"lessThan": "bfb74c48ac2d31476d5e09cf9658844508d2608a",
"versionType": "git",
"status": "affected"
},
{
"version": "ee122c79d4227f6ec642157834b6a90fcffa4382",
"lessThan": "081f22177d9d12b1e381b787f203cd5f47508187",
"versionType": "git",
"status": "affected"
},
{
"version": "ee122c79d4227f6ec642157834b6a90fcffa4382",
"lessThan": "be83178bfc44588f6e3adb827ed874c683193466",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.3",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.3",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.53",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.7",
"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/081f22177d9d12b1e381b787f203cd5f47508187",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/0d13b5a413bffc8718b3821b78537ccc6596c233",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/be83178bfc44588f6e3adb827ed874c683193466",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bfb74c48ac2d31476d5e09cf9658844508d2608a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fb78beb64e0e79557e4cd7cd17fea744bb6f01d9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}