CVE intelligence

CVE-2026-63823

Vulnerability intelligence

Published Jul 19, 2026Sources checked Oct 28, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-63823 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: Aug 14, 2026

CBL-Mariner Releases

Vendor-listed releases

6.6.150.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-63823?

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

keys: Pin request_key_auth payload in instantiate paths

A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ =========================

create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF

helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE**

Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state.

Hold that reference across the instantiate and reject paths. Drop the auth key owning reference from revoke and destroy.

[jarkko: Replaced the first two paragraphs of text with an actual concurrency scenario.]

Source: NVD