CVE-2026-74740
What it is
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain tcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking rcu_access_pointer(a->goto_chain) and then calling tcf_action_goto_chain_exec(), which does a second, independent rcu_dereference_bh(a->goto_chain) read and immediately dereferences chain->filter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact replace path) can clear a->goto_chain between the two reads, so the second read returns NULL and tcf_action_goto_chain_exec() dereferences NULL. Fix the race by doing a single rcu_dereference_bh() read of a->goto_chain in tcf_action_exec(), checking it once for NULL, and passing the resulting chain pointer into tcf_action_goto_chain_exec(). This turns the split check/use into a single check/use on one value.
At a glance
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: not scored yet.
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Received
Is it in your code?
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Read https://cve-list.com/agent/cve/CVE-2026-74740.md and follow it. Check whether this project is affected by CVE-2026-74740. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/1ec48b6715c29b20105e3485206602cff6c51ae5
- https://git.kernel.org/stable/c/28aa0c9dd0b1b38436995d4c15621ad3f896c7e3
- https://git.kernel.org/stable/c/6b70886ebc428eed43a069c8944a931b5fb3f4e4
- https://git.kernel.org/stable/c/91d55fd1fdb85c8371ca8793c788ea7d5192383a
- https://git.kernel.org/stable/c/abceabc4408fca6a9dd52611f5d197dec9390d63
- https://git.kernel.org/stable/c/f60b396ee174206fe08ebf997d16cd3801b77b22