Vulnerability in Linux

CVE-2026-90104

In the Linux kernel, the following vulnerability has been resolved: NFSv4.1: zero referring call lists before decoding decode_cb_sequence_args() allocates csa_rclists with kmalloc_objs(), so each referring_call_list starts uninitialized. decode_rc_list() assigns rcl_refcalls only when rcl_nrefcalls is nonzero. A valid list with zero referring calls therefore leaves the pointer uninitialized, and nfs4_callback_sequence() later passes stale slab contents to kfree(). Allocate csa_rclists with kzalloc_objs() so every rcl_refcalls member is NULL from the beginning, including valid empty referring call lists.

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.007 (52.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.5% 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-2026-90104: held from 0.006 to 0.007.

EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.001

Affected products

  • Linux — versions 2.6.31

References

Frequently asked questions

What is CVE-2026-90104?
CVE-2026-90104 is a critical-severity vulnerability in Linux. CVSS score: 9.8/10. Published 2026-09-17.
How severe is CVE-2026-90104?
Critical severity. CVSS v3 base score is 9.8 out of 10.