Use After Free in Linux

CVE-2025-37777

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __smb2_lease_break_noti() Move tcp_transport free to ksmbd_conn_free. If ksmbd connection is referenced when ksmbd server thread terminates, It will not be freed, but conn->tcp_transport is freed. __smb2_lease_break_noti can be performed asynchronously when the connection is disconnected. __smb2_lease_break_noti calls ksmbd_conn_write, which can cause use-after-free when conn->ksmbd_transport is already freed.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (28.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-37777: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

  • Linux — versions 0626e6641f6b467447c81dd7678a69c66f7746cf, 5.15, 0
  • Linux Kernel — versions 6.15

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-37777?
CVE-2025-37777 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 8.8/10. Published 2025-05-01.
How severe is CVE-2025-37777?
High severity. CVSS v3 base score is 8.8 out of 10.