CVE-2026-74690 s390/ism: Fix UAF of sba and ieq during ism_dev_exit()
A use-after-free vulnerability in the s390 ISM driver allows attackers to execute arbitrary code or escalate privileges via race conditions during device exit.
- 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-2026-74690?
CVE-2026-74690 is a high-severity use after free vulnerability in Linux, published on 22 Aug 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:
s390/ism: Fix UAF of sba and ieq during ism_dev_exit()
A ism interrupt handler can be active in parallel with ism_dev_exit(), accessing freed data structures.
No new interrupts will be generated after unregister_ieq(). Drain ongoing interrupt handlers by free_irq(), before freeing ism data structures.
Which versions are affected by CVE-2026-74690?
How do I fix CVE-2026-74690?
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-2026-74690 being exploited?
There is no known exploitation of CVE-2026-74690 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74690, DEBIAN-CVE-2026-74690, GHSA-f2p8-hwvr-fwmq, UBUNTU-CVE-2026-74690.