{"id":"CVE-2026-53218","summary":"netfilter: nft_exthdr: fix register tracking for F_PRESENT flag","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_exthdr: fix register tracking for F_PRESENT flag\n\nnft_exthdr_init() passes user-controlled priv-\u003elen to\nnft_parse_register_store(), which marks that many bytes in the\nregister bitmap as initialized.  However, when NFT_EXTHDR_F_PRESENT\nis set, the eval paths write only 1 byte (nft_reg_store8) or\n4 bytes (*dest = 0 on TCP/DCCP error path).  When len \u003e 4,\nregisters beyond the first are never written, retaining\nuninitialized stack data from nft_regs.\n\nBail out if userspace requests too much data when F_PRESENT is set.","modified":"2026-07-08T08:09:46.762203295Z","published":"2026-06-25T08:39:21.069Z","related":["CGA-5mxr-cm3h-vrh3"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53218.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237"},{"type":"WEB","url":"https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031"},{"type":"WEB","url":"https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134"},{"type":"WEB","url":"https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495"},{"type":"WEB","url":"https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53218.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53218"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c078ca3b0c5bf82c2b31906c446d6e2ad8ea0783"},{"fixed":"8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6"},{"fixed":"19748967d59c31d24d21d40b728570788310b237"},{"fixed":"46fc15a044e9938e7ea77786fb37edd2cd74f031"},{"fixed":"cd513e43b4b2bd1de39e2367bc4261c699a8652f"},{"fixed":"67b27434c43b68a97becda98c9f0c8cf6cba2134"},{"fixed":"78069a6d8bc86c9e036eb82c2af4a19cc1871a53"},{"fixed":"f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265"},{"fixed":"772cecf198da732faebb5dcfc46d66a505be8495"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53218.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.11.0"},{"fixed":"5.10.259"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.210"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.176"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.143"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.94"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.36"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53218.json"}}],"schema_version":"1.7.5"}