CVE-2026-74514 KVM: s390: pci: Fix memory accounting for pinned/unpinned pages
A reference counting error in KVM s390 PCI memory accounting allows local attackers to cause memory corruption, potentially leading to privilege escalation or denial of service.
- 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-2026-74514?
CVE-2026-74514 is a memory corruption vulnerability in Linux, published on 15 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:
KVM: s390: pci: Fix memory accounting for pinned/unpinned pages
The account_mem() and unaccount_mem() functions call get_uid() which increments the reference count of struct user_struct on every invocation. But we don't decrement the count by calling free_uid(). It also accounted/unaccounted the pages against the current->mm. But its possible the unaccount_mem() can be called from a different process context than the one that originally pinned the pages.
Let's fix this by storing the pinning process user_struct and mm_struct when accounting for pinned pages, and subsequently free these resources when the pages are unpinned.
[[email protected]: Fixed whitespace]
Which versions are affected by CVE-2026-74514?
How do I fix CVE-2026-74514?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74514 being exploited?
There is no known exploitation of CVE-2026-74514 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74514, DEBIAN-CVE-2026-74514, GHSA-rw3p-g3wm-qv8p, UBUNTU-CVE-2026-74514.