# CVE-2026-90120: irqchip/gic-v5: Check get_logical_index() return value in MADT IAFFID parsing

> A missing return value check in the Linux kernel GICv5 driver allows out-of-bounds memory corruption, potentially enabling code execution or privilege escalation.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-90120, GHSA-rfj6-7g8r-3866, UBUNTU-CVE-2026-90120

## What is CVE-2026-90120?

CVE-2026-90120 is a high-severity memory corruption vulnerability in Linux, published on 17 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:

irqchip/gic-v5: Check get_logical_index() return value in MADT IAFFID parsing

In gic_acpi_parse_iaffid() a given MADT GICC entry might not correspond
to a logical cpu recognized by the kernel, resulting in the cpu variable
initialization to an error value.

Currently, the get_logical_index() return value is not checked for failure,
which might result in out-of-bounds memory corruption while trying to
index a per_cpu variable array.

Add a check to evaluate get_logical_index() return value.

## Which versions are affected by CVE-2026-90120?


## How do I fix CVE-2026-90120?

Apply the vendor's patch.

## Is CVE-2026-90120 being exploited?

There is no known exploitation of CVE-2026-90120 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90120 and fix it if it is affected.

What it is: CVE-2026-90120 is a high-severity memory corruption vulnerability in Linux, published on 17 Sep 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-2026-90120 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-2026-90120/ (Markdown: https://insights.sbomify.com/CVE-2026-90120/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90120
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90120
- OSV: https://osv.dev/vulnerability/CVE-2026-90120

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90120/
Summaries are generated and may contain mistakes; the official description above is the record.