What is CVE-2026-31609?

CVE-2026-31609 is a critical-severity vulnerability in Linux, classified under Double Free. CVSS score: 9.8/10. Published 2026-04-24.

How severe is CVE-2026-31609?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Double Free in Linux

CVE-2026-31609

In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush() smbd_send_batch_flush() already calls smbd_free_send_io(), so we should not call it a…

Vulnerability class: Double Free

EPSS: 0.001 (20.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Linux — versions 6.18.24, 21538121efe6c8c5b51c742fa02cbe820bc48714, 7.0
Linux Linux_kernel

Weakness classification (CWE)

CWE-415 — Double Free

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)

Frequently asked questions

What is CVE-2026-31609?: CVE-2026-31609 is a critical-severity vulnerability in Linux, classified under Double Free. CVSS score: 9.8/10. Published 2026-04-24.
How severe is CVE-2026-31609?: Critical severity. CVSS v3 base score is 9.8 out of 10.