NULL pointer dereference in Linux

CVE-2025-21669

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: discard packets if the transport changes If the socket has been de-assigned or assigned to another transport, we must discard any packets received because they are not expected and would cause issues when we access vsk->transport. A possible scenario is described by Hyunwoo Kim in the attached link, where after a first connect() interrupted by a signal, and a second connect() failed, we can find `vsk->transport` at NULL, leading to a NULL pointer dereference.

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.002 (12.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.9% 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-2025-21669: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, 5.5, 0
  • Linux Kernel — versions 6.13

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21669?
CVE-2025-21669 is a high-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 7.8/10. Published 2025-01-31.
How severe is CVE-2025-21669?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21669 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.