Use of uninitialized resource in Linux kernel - CVE-2026-80543
Published: August 27, 2026
Vulnerability identifier: #VU145948
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-80543
CWE-ID: CWE-908
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to exposure of uninitialized memory in xcrb_msg_to_type6cprb_msgx() and xcrb_msg_to_type6_ep11cprb_msgx() in the s390 zcrypt message type 6 handling code when processing user-supplied CCA or EP11 messages with lengths that are not 4-byte aligned. A local user can submit a crafted message to disclose sensitive information.
Up to 3 bytes of uninitialized kernel memory may be forwarded to crypto card firmware during further processing.
Affected software
Linux kernel
How to mitigate CVE-2026-80543
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3