# CVE-2026-75083: The receive path of the NXP KW41Z IEEE 802.15.4 driver, kw41z_rx() in drivers/ieee802154/ieee802154_kw41z.c, computed the payload size as pk


- **Severity:** Medium 5.9 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** GHSA-2pwx-gg6f-535f

## What is CVE-2026-75083?

CVE-2026-75083 is a medium-severity vulnerability in zephyrproject zephyr, published on 14 Oct 2026. 

### Official description

The receive path of the NXP KW41Z IEEE 802.15.4 driver, kw41z_rx() in drivers/ieee802154/ieee802154_kw41z.c, computed the payload size as pkt_len = len - KW41Z_FCS_LENGTH in a uint8_t, where len is the frame length reported by the radio. The interrupt handler kw41z_isr() obtained that length from the RX_FRAME_LENGTH field of the ZLL IRQSTS register — a copy of the PHY header length byte of the frame received over the air — and only rejected the value zero. A reported length of one therefore underflowed to pkt_len == 255.

Because the packet is allocated with NET_AF_UNSPEC on a non-Ethernet L2, net_pkt_rx_alloc_with_buffer() does not clamp the request to the interface MTU; with the default fixed-size buffer pool (CONFIG_NET_BUF_FIXED_DATA_SIZE, CONFIG_NET_BUF_DATA_SIZE=128) the allocation succeeded as a chain of two fragments. The subsequent register-to-buffer copy loops write into the first fragment only, so 255 bytes were written into a 128-byte net_buf data block, overrunning it by up to 127 bytes into adjacent network-buffer-pool memory, and reading up to 128 bytes past the end of the radio's PKT_BUFFER_RX register array.

The length field originates from an unauthenticated frame transmitted by any device within 802.15.4 radio range, and is captured by the hardware at PHY-header time — before frame filtering has completed — while the handler samples it after clearing the interrupt status, so an attacker flooding frames with a length byte of one can drive the underflow. The impact is memory corruption in the shared receive buffer pool from interrupt context, most plausibly a crash or corruption of other packets' data; the overflowing bytes are radio register contents rather than attacker-authored data, which bounds the integrity impact.

The fix rejects any length below KW41Z_FCS_LENGTH and additionally verifies net_buf_tailroom() of the first fragment before the copy loops, which also covers the CONFIG_NET_L2_OPENTHREAD variant of the size computation.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-75083?


## How do I fix CVE-2026-75083?

No fix has been published for CVE-2026-75083 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-75083 being exploited?

There is no known exploitation of CVE-2026-75083 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75083 and fix it if it is affected.

What it is: CVE-2026-75083 is a medium-severity vulnerability in zephyrproject zephyr, published on 14 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-75083 in the wild and no public exploit code.

Affected product: zephyrproject zephyr. 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-2026-75083/ (Markdown: https://insights.sbomify.com/CVE-2026-75083/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75083
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75083
- OSV: https://osv.dev/vulnerability/CVE-2026-75083

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75083/
Summaries are generated and may contain mistakes; the official description above is the record.