CVE-2026-23261 nvme-fc: release admin tagset if init fails
A memory leak in the Linux kernel NVMe FC driver allows attackers to cause denial of service by triggering controller initialization failures.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23261?
CVE-2026-23261 is a medium-severity denial of service vulnerability in Linux kernel, published on 18 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nvme-fc: release admin tagset if init fails
nvme_fabrics creates an NVMe/FC controller in following path:
nvmf_dev_write() -> nvmf_create_ctrl() -> nvme_fc_create_ctrl() -> nvme_fc_init_ctrl()
nvme_fc_init_ctrl() allocates the admin blk-mq resources right after nvme_add_ctrl() succeeds. If any of the subsequent steps fail (changing the controller state, scheduling connect work, etc.), we jump to the fail_ctrl path, which tears down the controller references but never frees the admin queue/tag set. The leaked blk-mq allocations match the kmemleak report seen during blktests nvme/fc.
Check ctrl->ctrl.admin_tagset in the fail_ctrl path and call nvme_remove_admin_tag_set() when it is set so that all admin queue allocations are reclaimed whenever controller setup aborts.
Weakness: CWE-401
Which versions are affected by CVE-2026-23261?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23261?
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-2026-23261 being exploited?
There is no known exploitation of CVE-2026-23261 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23261, DEBIAN-CVE-2026-23261, GHSA-j54v-pxgx-56hg, ROOT-OS-DEBIAN-11-CVE-2026-23261, ROOT-OS-UBUNTU-2204-CVE-2026-23261, ROOT-OS-UBUNTU-2404-CVE-2026-23261 and 1 more.