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Vulnerability · Published May 27, 2026 · Assigned by Linux

CVE-2026-45841netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.1%top 97.2% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO nf_osf_match_one() computes ctx->window % f->wss.val in the OSF_WSS_MODULO branch with no guard for f->wss.val == 0. A CAP_NET_ADMIN user can add such a fingerprint via nfnetlink; a subsequent matching TCP SYN divides by zero and panics the kernel. Reject the bogus fingerprint in nfnl_osf_add_callback() above the per-option for-loop. f->wss is per-fingerprint, not per-option, so the check must run regardless of f->opt_num (including 0). Also reject wss.wc >= OSF_WSS_MAX; nf_osf_match_one() already treats that as "should not happen". Crash: Oops: divide error: 0000 [#1] SMP KASAN NOPTI RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98) Call Trace: <IRQ> nf_osf_match (net/netfilter/nfnetlink_osf.c:220) xt_osf_match_packet (net/netfilter/xt_osf.c:32) ipt_do_table (net/ipv4/netfilter/ip_tables.c:348) nf_hook_slow (net/netfilter/core.c:622) ip_local_deliver (net/ipv4/ip_input.c:265) ip_rcv (include/linux/skbuff.h:1162) __netif_receive_skb_one_core (net/core/dev.c:6181) process_backlog (net/core/dev.c:6642) __napi_poll (net/core/dev.c:7710) net_rx_action (net/core/dev.c:7945) handle_softirqs (kernel/softirq.c:622)

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.176-1DEBIAN-CVE-2026-45841
Debian:13linux6.12.94-1DEBIAN-CVE-2026-45841
Debian:14linux7.0.10-1DEBIAN-CVE-2026-45841
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2026-45841
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux7.0.0-28.28USN-8566-1
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9USN-8618-1
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1USN-8728-2
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8USN-8566-1
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1USN-8728-1
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4USN-8566-1
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10USN-8593-1
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16USN-8663-1
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1USN-8663-1
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16USN-8664-1
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9USN-8568-1
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8USN-8593-1
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1USN-8728-3
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2026-45841
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15USN-8618-1
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1USN-8566-1
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45841
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-45841
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-45841
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2026-45841
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2026-45841

Affected products (as reported)

VendorProductVersions
Linux Linux 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before cb833bbc1b3c51e08652d3c86298307c07d3f2db11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before 26900306a5a2c3e4f75c643a064525526bb6e5f311eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before 0694618cf3e9b120666e31f5f383a6e466d95a0d11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before 8def8fbd23f40e945febe913d04b731012ce008211eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before c55940895245d8ef658ab381248a28755218d62511eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before fb965b1cfe92b28d28b5ebe3116b81dbef9f2d2f11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before 9a05e195618a6d474f2bcd5b6376d0ffc2f0036611eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 – before 2195574dc6d9017d32ac346987e12659f931d932
Linux Linux 2.6.31

References