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7.8

CVE-2025-40149: Linux Kernel: setsockopt() Can Cause Data Loss

CVE-2025-40149 CVE-2025-40149
Summary

A bug in the Linux kernel's network code could cause data loss when using certain network settings. This issue has been fixed in a recent update. Affected users should update their Linux kernel to the latest version to prevent potential data loss.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software
VendorProductAffected versions
linux linux_kernel >= 4.18, < 5.15.199
>= 5.16, < 6.1.161
>= 6.2, < 6.6.121
>= 6.7, < 6.12.66
>= 6.13, < 6.17.3
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux < 2b1bef126bbb8d0da51491357559126d567c1dee
4.18
Original title
tls: Use __sk_dst_get() and dst_dev_rcu() in get_netdev_for_sock().
Original description
In the Linux kernel, the following vulnerability has been resolved:

tls: Use __sk_dst_get() and dst_dev_rcu() in get_netdev_for_sock().

get_netdev_for_sock() is called during setsockopt(),
so not under RCU.

Using sk_dst_get(sk)->dev could trigger UAF.

Let's use __sk_dst_get() and dst_dev_rcu().

Note that the only ->ndo_sk_get_lower_dev() user is
bond_sk_get_lower_dev(), which uses RCU.
nvd CVSS3.1 7.8
Vulnerability type
CWE-416 Use After Free
Published: 12 Nov 2025 · Updated: 14 Jul 2026 · First seen: 6 Mar 2026