CVE-2026-43409: linux NULL Pointer Dereference
Vulnerability summary
CVE-2026-43409 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.8% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 23 · Related 23Timeline
- 08-05-2026PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: kprobes: avoid crash when rmmod/insmod after ftrace killed After we hit ftrace is killed by some errors, the kernel crash if we remove modules in which kprobe probes. BUG: unable to handle page fault for address: fffffbfff805000d PGD 817fcc067 P4D 817fcc067 PUD 817fc8067 PMD 101555067 PTE 0 Oops: Oops: 0000 [#1] SMP KASAN PTI CPU: 4 UID: 0 PID: 2012 Comm: rmmod Tainted: G W OE Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE RIP: 0010:kprobes_module_callback+0x89/0x790 RSP: 0018:ffff88812e157d30 EFLAGS: 00010a02 RAX: 1ffffffff805000d RBX: dffffc0000000000 RCX: ffffffff86a8de90 RDX: ffffed1025c2af9b RSI: 0000000000000008 RDI: ffffffffc0280068 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1025c2af9a R10: ffff88812e157cd7 R11: 205d323130325420 R12: 0000000000000002 R13: ffffffffc0290488 R14: 0000000000000002 R15: ffffffffc0280040 FS: 00007fbc450dd740(0000) GS:ffff888420331000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff805000d CR3: 000000010f624000 CR4: 00000000000006f0 Call Trace: <TASK> notifier_call_chain+0xc6/0x280 blocking_notifier_call_chain+0x60/0x90 __do_sys_delete_module.constprop.0+0x32a/0x4e0 do_syscall_64+0x5d/0xfa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e This is because the kprobe on ftrace does not correctly handles the kprobe_ftrace_disabled flag set by ftrace_kill(). To prevent this error, check kprobe_ftrace_disabled in __disarm_kprobe_ftrace() and skip all ftrace related operations.
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
0.12%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
0.00 pp
From 0.12% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu157 products
- linuxAll versions (No fix recorded) | < 6.8.0-136.136
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1061.64
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b, < 8b6767e4141b2a42745b544d4555cf1614ba1a2d | ≥ ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b, < b0ca81616a010807e91fc31db9be242b96326adc | ≥ ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b, < cae928e3178c75602c21d67e21255d73e7e9ed4f | ≥ ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b, < 9edc79d664832a842012ad105b1521c1a3c35ab3 | ≥ ae6aa16fdc163afe6b04b6c073ad4ddd4663c03b, < e113f0b46d19626ec15388bcb91432c9a4fd6261 | 3.7
- linux_kernel≥ 3.7, < 6.6.130 | ≥ 6.7, < 6.12.78 | ≥ 6.13, < 6.18.19 | ≥ 6.19, < 6.19.9 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3
Debian1 product
- linuxAll versions (No fix recorded) | < 6.12.85-1 | < 6.19.10-1
3 vendors · 160 products