# CVE-2026-80802: nfc: fdp: bound the device-reported read length and fix an skb leak

> A malicious NFC controller can trigger a stack buffer overflow in the Linux kernel, potentially allowing code execution or system crashes.

- **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:** 4 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-99467, BELL-CVE-2026-80802, DEBIAN-CVE-2026-80802, GHSA-6fmj-x4q6-pp6w, UBUNTU-CVE-2026-80802

## What is CVE-2026-80802?

CVE-2026-80802 is a memory corruption vulnerability in Linux, published on 4 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: fdp: bound the device-reported read length and fix an skb leak

fdp_nci_i2c_read() takes the next packet length from two device-supplied
bytes and never validates it. The value is a u16 used as the
i2c_master_recv() count into a 261-byte on-stack buffer: a malicious,
counterfeit or malfunctioning controller (or an i2c bus interposer) can
drive it far past the buffer for a stack out-of-bounds write that
clobbers the canary and return address, or below the minimum frame size
(directly, or by truncating the computed sum) so the header/LRC strip
and the next length read run past a short receive. Reject a length
outside [FDP_NCI_I2C_MIN_PAYLOAD, FDP_NCI_I2C_MAX_PAYLOAD], as a
corrupted packet already is, and force resynchronization.

The same loop allocates one data skb per iteration and assumes a length
packet followed by a data packet; a device that sends two data packets
in one call leaks the first skb when the second allocation overwrites
it. Free a previously allocated skb before allocating the next.

## Which versions are affected by CVE-2026-80802?


## How do I fix CVE-2026-80802?

Apply the vendor's patch.

## Is CVE-2026-80802 being exploited?

There is no known exploitation of CVE-2026-80802 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80802 and fix it if it is affected.

What it is: CVE-2026-80802 is a memory corruption vulnerability in Linux, published on 4 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-2026-80802 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-2026-80802/ (Markdown: https://insights.sbomify.com/CVE-2026-80802/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80802
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80802
- OSV: https://osv.dev/vulnerability/CVE-2026-80802

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80802/
Summaries are generated and may contain mistakes; the official description above is the record.