{"id":"AZL-88644","summary":"CVE-2026-45841 affecting package kernel for versions less than 6.6.141.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO\n\nnf_osf_match_one() computes ctx-\u003ewindow % f-\u003ewss.val in the\nOSF_WSS_MODULO branch with no guard for f-\u003ewss.val == 0. A\nCAP_NET_ADMIN user can add such a fingerprint via nfnetlink; a\nsubsequent matching TCP SYN divides by zero and panics the kernel.\n\nReject the bogus fingerprint in nfnl_osf_add_callback() above the\nper-option for-loop. f-\u003ewss is per-fingerprint, not per-option, so\nthe check must run regardless of f-\u003eopt_num (including 0). Also\nreject wss.wc \u003e= OSF_WSS_MAX; nf_osf_match_one() already treats that\nas \"should not happen\".\n\nCrash:\n Oops: divide error: 0000 [#1] SMP KASAN NOPTI\n RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98)\n Call Trace:\n \u003cIRQ\u003e\n  nf_osf_match (net/netfilter/nfnetlink_osf.c:220)\n  xt_osf_match_packet (net/netfilter/xt_osf.c:32)\n  ipt_do_table (net/ipv4/netfilter/ip_tables.c:348)\n  nf_hook_slow (net/netfilter/core.c:622)\n  ip_local_deliver (net/ipv4/ip_input.c:265)\n  ip_rcv (include/linux/skbuff.h:1162)\n  __netif_receive_skb_one_core (net/core/dev.c:6181)\n  process_backlog (net/core/dev.c:6642)\n  __napi_poll (net/core/dev.c:7710)\n  net_rx_action (net/core/dev.c:7945)\n  handle_softirqs (kernel/softirq.c:622)","modified":"2026-08-28T17:47:37.432247145Z","published":"2026-05-27T11:16:23Z","upstream":["CVE-2026-45841"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45841"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.141.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-88644.json"}}],"schema_version":"1.9.0"}