CVE-2026-63823

High

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.]

Package Linux Kernel
Published 2026-07-19
Last modified 2026-08-17
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 2.6.16 and later are affected. Fixed in 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2 and their respective stable series.

Affected from
≥ 2.6.16
Fixed in
✓ 5.10.260 5.10.x ✓ 5.15.211 5.15.x ✓ 6.1.177 6.1.x ✓ 6.6.144 6.6.x ✓ 6.12.95 6.12.x ✓ 6.18.38 6.18.x ✓ 7.1.3 7.1.x ✓ 7.2

Frequently asked questions

  • What is CVE-2026-63823?

    CVE-2026-63823 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 2.6.16 onward and has been patched in 5.10.260, 5.15.211, 6.1.177 and others. CVE-2026-63823 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-63823?

    CVE-2026-63823 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-63823?

    Yes. CVE-2026-63823 has been patched. Fixed versions include 5.10.260, 5.15.211, 6.1.177 and others. If you are running Linux kernel 2.6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-63823 actively exploited?

    No. CVE-2026-63823 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.