Use-after-free in Linux kernel - CVE-2026-64439
Published: July 27, 2026
Vulnerability identifier: #VU139502
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64439
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in krb5 AEAD encryption and decryption helpers when processing operations with an async AEAD implementation. A local user can trigger crypto operations using an async AEAD provider to cause a denial of service.
The issue is reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c, and net/ceph/crypto.c only on systems with an async AEAD provider bound to the krb5 enctype name.
How to mitigate CVE-2026-64439
Install security update from vendor's repository.