# CVE-2026-90221: nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing

> A local attacker can trigger uninitialized memory reads in the Linux kernel NFC subsystem, potentially disclosing sensitive kernel memory contents.

- **Severity:** Not scored
- **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:** AZL-102122, BELL-CVE-2026-90221, DEBIAN-CVE-2026-90221, GHSA-h298-hpmc-3w4v, UBUNTU-CVE-2026-90221

## What is CVE-2026-90221?

CVE-2026-90221 is a 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:

nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing

nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse
the CORE_INIT_RSP packet without validating that the skb contains
enough data. A malformed response (e.g. injected via virtual_ncidev)
can declare a large num_supported_rf_interfaces while providing
insufficient data, causing reads of uninitialized slab memory. This
is later used in nci_init_complete_req(), triggering a KMSAN
uninit-value warning.

Add skb length checks before accessing packet fields:
- Validate the skb has at least 1 byte for the status field.
- Validate the skb can hold the fixed-size header before parsing.
- In v2, bounds-check each variable-length rf_interface entry and its
  extension parameters within the parsing loop.
- In v1, verify the skb is large enough for both the variable-length
  rf_interfaces array and the trailing rsp_2 structure.

## Which versions are affected by CVE-2026-90221?


## How do I fix CVE-2026-90221?

Apply the vendor's patch.

## Is CVE-2026-90221 being exploited?

There is no known exploitation of CVE-2026-90221 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90221 and fix it if it is affected.

What it is: CVE-2026-90221 is a 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-2026-90221 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-2026-90221/ (Markdown: https://insights.sbomify.com/CVE-2026-90221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90221
- OSV: https://osv.dev/vulnerability/CVE-2026-90221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90221/
Summaries are generated and may contain mistakes; the official description above is the record.