CVE-2026-43086
What it is
In 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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Analyzed
Affected
- Linux Kernel < 6.6.136
- Linux Kernel < 6.12.83
- Linux Kernel < 6.18.24
- Linux Kernel < 6.19.14
- Linux Kernel 6.2
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-43086.md and follow it. Check whether this project is affected by CVE-2026-43086. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/4039959315008888dd53c37674d33351817a5166
- https://git.kernel.org/stable/c/730663352c9178f33fcf5929f4a37c1f1ca5a693
- https://git.kernel.org/stable/c/9a91797e61d286805ae10a92cc48959c30800556
- https://git.kernel.org/stable/c/a32dabacee111cea083ddd57a03635672e1bff29
- https://git.kernel.org/stable/c/c2ddbe577e2ebf63f2d8fb15cdc7503af70f3e94
References
- https://git.kernel.org/stable/c/4039959315008888dd53c37674d33351817a5166
- https://git.kernel.org/stable/c/730663352c9178f33fcf5929f4a37c1f1ca5a693
- https://git.kernel.org/stable/c/9a91797e61d286805ae10a92cc48959c30800556
- https://git.kernel.org/stable/c/a32dabacee111cea083ddd57a03635672e1bff29
- https://git.kernel.org/stable/c/c2ddbe577e2ebf63f2d8fb15cdc7503af70f3e94