CVE-2026-90337 serial: core: do fallible allocations before the console can be registered
A use-after-free vulnerability in the Linux kernel serial core allows local attackers to cause a denial of service or potentially execute code via failed port bindings.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90337?
CVE-2026-90337 is an use after free vulnerability in Linux, published on 17 Sep 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:
serial: core: do fallible allocations before the console can be registered
serial_core_add_one_port() allocates uport->tty_groups after uart_configure_port(), which may register the console. If the allocation fails, the driver unwinds the port while its console remains registered. The earlier uport->name allocation has a related failure path that leaves state->uart_port linked to a port being freed.
Failslab reproduced a NULL dereference in PL011 console output and a KASAN use-after-free in i.MX console output after failed binds.
Allocate the name and tty_groups before linking the port and configuring it. Reserve space for the optional driver attribute group because config_port() may populate uport->attr_group during configuration.
Which versions are affected by CVE-2026-90337?
How do I fix CVE-2026-90337?
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-2026-90337 being exploited?
There is no known exploitation of CVE-2026-90337 in the wild and no public exploit code.
Sources
Also known as AZL-102414, BELL-CVE-2026-90337, DEBIAN-CVE-2026-90337, GHSA-3m6c-788w-h698, UBUNTU-CVE-2026-90337.