CVE-2026-45841 Details
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)
A divide-by-zero vulnerability has been identified in the Linux kernel's netfilter component, specifically within the nfnetlink_osf module. This issue arises in the nf_osf_match_one() function, where the OSF_WSS_MODULO branch computes a value based on window size without checking if the divisor is zero. A user with CAP_NET_ADMIN privileges can exploit this by adding a malicious fingerprint through nfnetlink. When a matching TCP SYN packet is processed, the division by zero occurs, causing a kernel panic. The vulnerability has been addressed by adding validation to reject such fingerprints before processing, ensuring that the wss.val is not zero and that wss.wc is within acceptable limits.
Users can update to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for updating the kernel can be found in the official Linux documentation or through the package management system for the specific Linux distribution in use.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-369 | Divide By Zero | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 2.6.31, < 5.10.258 >= 5.11, < 5.15.209 >= 5.16, < 6.1.175 >= 6.2, < 6.6.141 >= 6.7, < 6.12.91 >= 6.13, < 6.18.33 >= 6.19, < 7.0.10 |
CPE
Remediation
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Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 8, 2026 | CVE Modified | kernel.org |
| Sep 8, 2026 | CVE Modified | siemens-SADP |
| Jun 26, 2026 | Initial Analysis | [email protected] |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jun 1, 2026 | CVE Modified | kernel.org |
| May 27, 2026 | New CVE Received | kernel.org |