{"id":"CVE-2026-53218","title":"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->len to\nnft_parse_register_store(), which marks that many…","summary":"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->len to\nnft_parse_register_store(), which marks that many…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-908"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.11, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T09:18:14.403","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53218","references":[{"url":"https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00125,"epssPercentile":0.02564,"ingestedAt":"2026-07-03T13:02:28.053Z","slug":"CVE-2026-53218","body":"## Overview\n\nIn 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->len 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 > 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.\n\n## Affected\n\n- `linux_kernel >= 4.11, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}