{"id":"CVE-2026-31428","state":"PUBLISHED","title":"netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD\n\n__build_packet_message() manually constructs the NFULA_PAYLOAD netlink\nattribute using skb_put() and skb_copy_bits(), bypassing the standard\nnla_reserve()/nla_put() helpers. While nla_total_size(data_len) bytes\nare allocated (including NLA alignment padding), only data_len bytes\nof actual packet data are copied. The trailing nla_padlen(data_len)\nbytes (1-3 when data_len is not 4-byte aligned) are never initialized,\nleaking stale heap contents to userspace via the NFLOG netlink socket.\n\nReplace the manual attribute construction with nla_reserve(), which\nhandles the tailroom check, header setup, and padding zeroing via\n__nla_reserve(). The subsequent skb_copy_bits() fills in the payload\ndata on top of the properly initialized attribute.","publishedAt":"2026-04-13T13:40:30.987Z","updatedAt":"2026-10-15T01:16:10.258Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"7f3e5d72455936f42709116fabeca3bb216cda62","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"21d8efda029948d3666b0db5afcc0d36c0984aae","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"fc961dd7272b5e4a462999635e44a4770d7f2482","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"a8365d1064ded323797c5e28e91070c52f44b76c","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"a2f6ff3444b663d6cfa63eadd61327a18592885a","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"c9f6c51d36482805ac3ffadb9663fe775a13e926","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"7eff72968161fb8ddb26113344de3b92fb7d7ef5","versionType":"git"},{"version":"df6fb868d6118686805c2fa566e213a8f31c8e4f","status":"affected","lessThan":"52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nfnetlink_log.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.24","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.24","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.131","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.80","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.21","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nfnetlink_log.c"]}],"references":["https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62","https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae","https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482","https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c","https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a","https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926","https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5","https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7","https://cert-portal.siemens.com/productcert/html/ssa-082556.html","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31428.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31428","state":"PUBLISHED","datePublished":"2026-04-13T13:40:30.987Z","dateUpdated":"2026-10-15T01:16:10.258Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.089Z"},"containers":{"cna":{"title":"netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD\n\n__build_packet_message() manually constructs the NFULA_PAYLOAD netlink\nattribute using skb_put() and skb_copy_bits(), bypassing the standard\nnla_reserve()/nla_put() helpers. 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