CVE-2026-45841: linux Divide By Zero
Vulnerability summary
CVE-2026-45841 is a medium (CVSS 5.5) Divide By Zero vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 50 · Related 50Timeline
- 27-05-2026PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
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)
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
6%
Versus all other CVEs
30-day change
+0.04 pp
From 0.13% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu166 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < cb833bbc1b3c51e08652d3c86298307c07d3f2db | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < 26900306a5a2c3e4f75c643a064525526bb6e5f3 | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < 0694618cf3e9b120666e31f5f383a6e466d95a0d | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < 8def8fbd23f40e945febe913d04b731012ce0082 | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < c55940895245d8ef658ab381248a28755218d625 | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < fb965b1cfe92b28d28b5ebe3116b81dbef9f2d2f | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < 9a05e195618a6d474f2bcd5b6376d0ffc2f00366 | ≥ 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, < 2195574dc6d9017d32ac346987e12659f931d932 | 2.6.31
- 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
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.10-1
3 vendors · 169 products
