CVE-2026-74466: s390/zcrypt: Close speculative mem read possibility
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: Close speculative mem read possibility
The domain value is extracted from a given CCA or EP11 ioctl struct when a CPRB is about to be sent. Thus this is a user controlled value. Under some special conditions (custom device node used, administrative load) this value is used as an array index after bounds checking, but without speculation barrier.
Add the missing arrayindexnospec() call to prevent speculative execution where this domain value is used.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.114 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.57 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 7.1.8 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 7.1.8-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 7.2.12-1Fixed in 7.2.14-1 - Compensating control
Add the missing array_index_nospec() call before using the user-controlled domain value as an array index in the s390/zcrypt CCA or EP11 ioctl CPRB path, to prevent speculative execution.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-74466?
CVE-2026-74466 has a risk rating of 19, indicating a significant security concern.
How do I fix CVE-2026-74466?
To address CVE-2026-74466, ensure that you update the Linux kernel to the latest patched version.
What systems are affected by CVE-2026-74466?
CVE-2026-74466 affects systems running vulnerable versions of the Linux kernel that utilize s390/zcrypt.
What is the impact of CVE-2026-74466?
CVE-2026-74466 can lead to potential leakage of sensitive information through speculative memory reads.
When was CVE-2026-74466 published?
CVE-2026-74466 was published on August 15, 2026.