Linux KernelOperating system · Linux
CVE-2026-43086
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: ipvs: fix NULL deref in ip_vs_add_service error path When ip_vs_bind_scheduler() succeeds in ip_vs_add_service(), the local variable sched is set to NULL. If ip_vs_start_estimator() subsequently fails, the out_err cleanup calls ip_vs_unbind_scheduler(svc, sched) with sched == NULL. ip_vs_unbind_scheduler() passes the cur_sched NULL check (because svc->scheduler was set by the successful bind) but then dereferences the NULL sched parameter at sched->done_service, causing a kernel panic at offset 0x30 from NULL. Oops: general protection fault, [..] [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] RIP: 0010:ip_vs_unbind_scheduler (net/netfilter/ipvs/ip_vs_sched.c:69) Call Trace: <TASK> ip_vs_add_service.isra.0 (net/netfilter/ipvs/ip_vs_ctl.c:1500) do_ip_vs_set_ctl (net/netfilter/ipvs/ip_vs_ctl.c:2809) nf_setsockopt (net/netfilter/nf_sockopt.c:102) [..] Fix by simply not clearing the local sched variable after a successful bind. ip_vs_unbind_scheduler() already detects whether a scheduler is installed via svc->scheduler, and keeping sched non-NULL ensures the error path passes the correct pointer to both ip_vs_unbind_scheduler() and ip_vs_scheduler_put(). While the bug is older, the problem popups in more recent kernels (6.2), when the new error path is taken after the ip_vs_start_estimator() call.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.
General guidance for the null pointer dereference class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 6.2.1, < 6.6.136>= 6.7, < 6.12.83>= 6.13, < 6.18.24>= 6.19, < 6.19.14= 6.2= 7.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped6.6.1366.12.836.18.24
Kernel 6.6.136 (for 6.2.1-6.6.x), 6.12.83 (for 6.7-6.12.x), 6.18.24 (for 6.13-6.18.x), or 6.19.14 (for 6.19.x)
- Identify the currently running kernel version using `uname -r`
- Check which kernel branch your version belongs to (6.2.1-6.6.x, 6.7-6.12.x, 6.13-6.18.x, or 6.19.x)
- For 6.2.1 <= version < 6.6.136: upgrade to kernel 6.6.136 or later
- For 6.7 <= version < 6.12.83: upgrade to kernel 6.12.83 or later
- For 6.13 <= version < 6.18.24: upgrade to kernel 6.18.24 or later
- For 6.19 <= version < 6.19.14: upgrade to kernel 6.19.14 or later
- Alternatively, apply the vendor patch commit 4039959315008888dd53c37674d33351817a5166 to the kernel source and rebuild
- After upgrade, verify the fix by checking the kernel version with `uname -r`
Generated from the published advisory — verify against the referenced sources before acting.
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Free · runs locallyCheck whether your project pulls in CVE-2026-43086 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-43086 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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