CVE-2026-98748 serial: 8250_bcm7271: fix use-after-free in brcmuart_remove()
A use-after-free in the BCM7271 serial driver allows local attackers to execute code or crash the system when hardware flow control is enabled.
- 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-2026-98748?
CVE-2026-98748 is an use after free vulnerability in Linux, published on 18 Oct 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: 8250_bcm7271: fix use-after-free in brcmuart_remove()
brcmuart_handle_irq() starts priv->hrt to work around a receive-timeout quirk of the 8250 core when hardware flow control is enabled; the timer callback brcmuart_hrtimer_func() dereferences priv.
brcmuart_remove() cancels the hrtimer before it unregisters the port, so a receive-timeout interrupt that arrives in between re-arms the timer. After devm frees priv, the callback runs on freed memory.
Unregister the port before cancelling the hrtimer. serial8250_unregister_port() shuts the port down and frees its IRQ, so brcmuart_handle_irq() can no longer restart the timer, and the final hrtimer_cancel() drains any timer that was armed before or during the unregister.
This issue was found by an in-house static analysis tool.
Which versions are affected by CVE-2026-98748?
How do I fix CVE-2026-98748?
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-2026-98748 being exploited?
There is no known exploitation of CVE-2026-98748 in the wild and no public exploit code.
Sources
Also known as AZL-109419, BELL-CVE-2026-98748, DEBIAN-CVE-2026-98748, GHSA-7g75-q55x-6r4j, UBUNTU-CVE-2026-98748.