What is CVE-2025-40139?

CVE-2025-40139 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-11-12.

How severe is CVE-2025-40139?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in Linux

CVE-2025-40139

In the Linux kernel, the following vulnerability has been resolved: smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set(). smc_clc_prfx_set() is called during connect() and not under RCU nor RTNL. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dev_dst_rcu() under rcu_read_lock() after kernel_getsockname(). Note that the returned value of smc_clc_prfx_set() is not used in the caller. While at it, we change the 1st arg of smc_clc_prfx_set[46]_rcu() not to touch dst there.

EPSS: 0.002 (8.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Linux — versions a046d57da19f812216f393e7c535f5858f793ac3, 4.11, 0

References

Frequently asked questions

What is CVE-2025-40139?: CVE-2025-40139 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-11-12.
How severe is CVE-2025-40139?: High severity. CVSS v3 base score is 7.8 out of 10.