# CVE-2026-80796: nfc: nci: add data_len bound checks to activation parameter extractors

> A missing bounds check in the Linux kernel NFC driver allows attackers to read kernel memory or cause a crash via crafted NCI notifications.

- **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-99507, BELL-CVE-2026-80796, DEBIAN-CVE-2026-80796, GHSA-x2c2-6crc-q5ch, UBUNTU-CVE-2026-80796

## What is CVE-2026-80796?

CVE-2026-80796 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: nci: add data_len bound checks to activation parameter extractors

nci_extract_activation_params_iso_dep() and
nci_extract_activation_params_nfc_dep() read an inner length byte from
the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed
kernel buffers, but neither function receives the caller-validated
activation_params_len.  A crafted NCI notification with
activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or
50 (NFC-B) causes memcpy() to read that many bytes past the one valid
byte in the activation params region -- a slab out-of-bounds read of
kernel memory adjacent to the NCI skb.

The sibling nci_extract_rf_params_*() family was given equivalent
protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter
validation for packet data"), but the two activation parameter
extractors were not updated at that time.

Add a data_len parameter to both functions, guard against an empty
region before consuming the inner length byte, decrement the remaining
count after consuming it, and clamp the copy length to what is actually
available.  Update both call sites to pass ntf.activation_params_len,
which is already validated against the skb at ntf.c:801.

## Which versions are affected by CVE-2026-80796?


## How do I fix CVE-2026-80796?

Apply the vendor's patch.

## Is CVE-2026-80796 being exploited?

There is no known exploitation of CVE-2026-80796 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80796 and fix it if it is affected.

What it is: CVE-2026-80796 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-2026-80796 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-2026-80796/ (Markdown: https://insights.sbomify.com/CVE-2026-80796/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80796
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80796
- OSV: https://osv.dev/vulnerability/CVE-2026-80796

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80796/
Summaries are generated and may contain mistakes; the official description above is the record.