CVE intelligence

CVE-2025-21863

Vulnerability intelligence

Published Mar 12, 2025Sources checked Nov 14, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2025-21863 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Sep 29, 2026

CBL-Mariner Releases Release Notes

Vendor-listed releases

6.6.82.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2025-21863?

In the Linux kernel, the following vulnerability has been resolved:

io_uring: prevent opcode speculation

sqe->opcode is used for different tables, make sure we santitise it against speculations.

Source: NVD