CVE-2026-43373 net: ncsi: fix skb leak in error paths
A memory leak in the Linux kernel NCSI driver allows attackers to cause denial of service by triggering error paths that fail to release network buffers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43373?
CVE-2026-43373 is a high-severity denial of service vulnerability in Linux kernel, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: ncsi: fix skb leak in error paths
Early return paths in NCSI RX and AEN handlers fail to release the received skb, resulting in a memory leak.
Specifically, ncsi_aen_handler() returns on invalid AEN packets without consuming the skb. Similarly, ncsi_rcv_rsp() exits early when failing to resolve the NCSI device, response handler, or request, leaving the skb unfreed.
Weakness: CWE-401
Which versions are affected by CVE-2026-43373?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43373?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-43373 being exploited?
There is no known exploitation of CVE-2026-43373 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43373, DEBIAN-CVE-2026-43373, GHSA-cc5x-4c4f-8gxf, ROOT-OS-DEBIAN-11-CVE-2026-43373, ROOT-OS-UBUNTU-2204-CVE-2026-43373, ROOT-OS-UBUNTU-2404-CVE-2026-43373 and 1 more.