# 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.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 23 Aug 2026
- **Also known as:** BELL-CVE-2026-74514, DEBIAN-CVE-2026-74514, GHSA-rw3p-g3wm-qv8p, UBUNTU-CVE-2026-74514

## 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.

[borntraeger@linux.ibm.com: Fixed whitespace]

## Which versions are affected by CVE-2026-74514?


## How do I fix CVE-2026-74514?

Apply the vendor's patch.

## Is CVE-2026-74514 being exploited?

There is no known exploitation of CVE-2026-74514 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74514 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-74514 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74514/ (Markdown: https://insights.sbomify.com/CVE-2026-74514/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74514
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74514
- OSV: https://osv.dev/vulnerability/CVE-2026-74514

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74514/
Summaries are generated and may contain mistakes; the official description above is the record.