wifi: mac80211: defer link RX stats percpu free to RCU
CVE-2026-68409 · published 10 Aug 2026
How serious is it
- Severity: high, CVSS score 8.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-68409?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: c71420db653aba30a234d1e4cf86dde376e604fa to < a5afc00280986063f1c355821544fabbb2a960f7, c71420db653aba30a234d1e4cf86dde376e604fa to < b679c1cffb2f3d0854b8b05ea9e909ad6489046f, c71420db653aba30a234d1e4cf86dde376e604fa to < 2aa1789880fa5e41049b0f6a74a4fc2fa1997610, c71420db653aba30a234d1e4cf86dde376e604fa to < a03fceae0c65b31ce31840dac5e26684ceecb65b
- Linux Linux: 6.0
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: defer link RX stats percpu free to RCU
sta_remove_link() frees a removed MLO link's RX stats percpu buffer right
away, but defers only the link container to RCU:
sta_info_free_link(&alloc->info);
kfree_rcu(alloc, rcu_head);
The RX fast path reads link_sta under rcu_read_lock and writes the percpu
stats. A reader that resolved link_sta before the removal keeps the
pointer. The container stays alive from the kfree_rcu, so the read still
works. But the percpu block it points to is already freed. This needs
uses_rss. That is when pcpu_rx_stats exists.
The full STA teardown frees the deflink stats only after
synchronize_net(). The link removal path had no such barrier. The race is
hard to win in practice, but the free should still wait for RCU.
Free the link together with its data from a single RCU callback, so the
percpu block is reclaimed only after readers drain.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/a5afc00280986063f1c355821544fabbb2a960f7
- git.kernel.org/stable/c/b679c1cffb2f3d0854b8b05ea9e909ad6489046f
- git.kernel.org/stable/c/2aa1789880fa5e41049b0f6a74a4fc2fa1997610
- git.kernel.org/stable/c/a03fceae0c65b31ce31840dac5e26684ceecb65b
- git.kernel.org/stable/c/aa2eb62525188269cdd402a583b9a8ed94657ff0
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON