Vulnerability in Linux

CVE-2025-39815

In the Linux kernel, the following vulnerability has been resolved: RISC-V: KVM: fix stack overrun when loading vlenb The userspace load can put up to 2048 bits into an xlen bit stack buffer. We want only xlen bits, so check the size beforehand.

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 (3.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.8% 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-2025-39815: 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 2fa290372dfe7dd248b1c16f943f273a3e674f22, 6.8, 0
  • Linux Kernel — versions 6.17

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-39815?
CVE-2025-39815 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-09-16.
How severe is CVE-2025-39815?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-39815 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.