NULL pointer dereference in Linux

CVE-2026-23309

In the Linux kernel, the following vulnerability has been resolved: tracing: Add NULL pointer check to trigger_data_free() If trigger_data_alloc() fails and returns NULL, event_hist_trigger_parse() jumps to the out_free error path. While kfree() safely handles a NULL pointer, trigger_data_free() does not. This causes a NULL pointer dereference in trigger_data_free() when evaluating data->cmd_ops->set_filter. Fix the problem by adding a NULL pointer check to trigger_data_free(). The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.8% 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-2026-23309: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

  • Linux — versions c10f0efe57728508d796ae4ba7abe4c14ec3d8ef, 7e6556e9329bc484e9dcdab6e346d959267c0636, 9b0513905e0598b9f8cfccab8e47497aed5d935d
  • Linux Kernel — versions 7.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23309?
CVE-2026-23309 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-03-25.
How severe is CVE-2026-23309?
Medium severity. CVSS v3 base score is 5.5 out of 10.