CVE-2026-89964 parisc: eisa: Fix infinite loop when parsing invalid IRQ value
An attacker with kernel command line access can cause a denial of service via an infinite loop during boot when parsing invalid EISA IRQ values.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89964?
CVE-2026-89964 is a denial of service vulnerability in Linux, published on 16 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:
parisc: eisa: Fix infinite loop when parsing invalid IRQ value
When an invalid value is passed via the "eisa_irq_edge=" kernel command line parameter (e.g. "eisa_irq_edge=16,5"), eisa_irq_setup() prints an error message and continues without advancing the current position. As a result the same invalid value is parsed again and again, causing an infinite loop while the kernel boots.
Advance to the next comma-separated entry, or stop parsing when there is no next entry, before continuing so that the remaining entries are processed normally.
Which versions are affected by CVE-2026-89964?
How do I fix CVE-2026-89964?
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-2026-89964 being exploited?
There is no known exploitation of CVE-2026-89964 in the wild and no public exploit code.
Sources
Also known as AZL-101442, BELL-CVE-2026-89964, DEBIAN-CVE-2026-89964, GHSA-w8m9-w285-5x2j, UBUNTU-CVE-2026-89964.