{"id":"CVE-2026-97965","title":"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 us…","summary":"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 us…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ee122c79d4227f6ec642157834b6a90fcffa4382 < 0d13b5a413bffc8718b3821b78537ccc6596c233","Linux >= ee122c79d4227f6ec642157834b6a90fcffa4382 < bfb74c48ac2d31476d5e09cf9658844508d2608a","Linux >= ee122c79d4227f6ec642157834b6a90fcffa4382 < 081f22177d9d12b1e381b787f203cd5f47508187","Linux >= ee122c79d4227f6ec642157834b6a90fcffa4382 < be83178bfc44588f6e3adb827ed874c683193466","Linux 4.3"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:24.293","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97965","references":[{"url":"https://git.kernel.org/stable/c/081f22177d9d12b1e381b787f203cd5f47508187","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0d13b5a413bffc8718b3821b78537ccc6596c233","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/be83178bfc44588f6e3adb827ed874c683193466","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bfb74c48ac2d31476d5e09cf9658844508d2608a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.873Z","slug":"CVE-2026-97965","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}