{"id":"AZL-96600","summary":"CVE-2026-74579 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_payload: fix mask build for partial field offload\n\nnft_payload_offload_mask() builds the offload match mask for a payload\nexpression that covers only part of a header field.  For a partial IPv6\naddress match (field_len = 16, priv_len = 1) that shift is 1 \u003c\u003c 120, which\nis undefined on the 32-bit int operand.  It also trims only one word, so\nthe remaining words stay 0xffffffff (and when priv_len is a multiple of 4\nthe trim is skipped entirely), leaving the mask covering more bytes than\nthe rule matches.\n\n  UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20\n  shift exponent 120 is too large for 32-bit type 'int'\n  ...\n\nThe match is byte-granular and struct nft_data is zero-initialised, so the\ncorrect mask is simply the first priv_len bytes set to 0xff. Set those\nbytes directly and drop the word/shift trimming; this removes the undefined\nshift and no longer over-masks the trailing bytes.","modified":"2026-09-21T05:34:22Z","published":"2026-08-17T06:19:56Z","upstream":["CVE-2026-74579"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74579"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-96600.json"}}],"schema_version":"1.9.0"}