{"cve":"CVE-2026-97965","nvd":{"published":"2026-09-25T11:17:24.293","modified":"2026-10-21T13:21:17.963","status":"Received","description":"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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/081f22177d9d12b1e381b787f203cd5f47508187","https://git.kernel.org/stable/c/0d13b5a413bffc8718b3821b78537ccc6596c233","https://git.kernel.org/stable/c/be83178bfc44588f6e3adb827ed874c683193466","https://git.kernel.org/stable/c/bfb74c48ac2d31476d5e09cf9658844508d2608a","https://git.kernel.org/stable/c/fb78beb64e0e79557e4cd7cd17fea744bb6f01d9"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-97965","score":0.00168,"percentile":0.06157,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}