CVE-2026-80862 nvme-tcp: fix usage of page_frag_cache
A race condition in the Linux kernel's NVMe-TCP driver causes premature page freeing, leading to system crashes or potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80862?
CVE-2026-80862 is an use after free vulnerability in Linux, published on 4 Sep 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:
nvme-tcp: fix usage of page_frag_cache
nvme uses page_frag_cache to preallocate PDU for each preallocated request of block device. Block devices are created in parallel threads, consequently page_frag_cache is used in not thread-safe manner. That leads to incorrect refcounting of backstore pages and premature free.
That can be catched by !sendpage_ok inside network stack:
WARNING: CPU: 7 PID: 467 at ../net/core/skbuff.c:6931 skb_splice_from_iter+0xfa/0x310. tcp_sendmsg_locked+0x782/0xce0 tcp_sendmsg+0x27/0x40 sock_sendmsg+0x8b/0xa0 nvme_tcp_try_send_cmd_pdu+0x149/0x2a0 Then random panic may occur.
Fix that by serializing the usage of page_frag_cache.
Which versions are affected by CVE-2026-80862?
How do I fix CVE-2026-80862?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-80862 being exploited?
There is no known exploitation of CVE-2026-80862 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80862, DEBIAN-CVE-2026-80862, GHSA-r23c-4v3q-555g, UBUNTU-CVE-2026-80862.