CVE-2026-89920
What it is
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix memory corruption by not reinjecting CK machine checks Channel-subsystem damage machine checks are for the host channel subsystem. The guest channel subsystem is emulated in the userspace VMM. There is no point in forwarding such machine checks into the guest. This also simplifies the machine check reinjection and avoids kfree of a stack variable as reported by sashiko. There might be still machine checks that have the ck bit set with another bit (like instruction damage), mask out the CK bit in s390_backup_mcck_info(), like the CP and ED bits already are.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-89920.md and follow it. Check whether this project is affected by CVE-2026-89920. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/045f3e95a0deccb277c29bd003e1d43c0ad40c90
- https://git.kernel.org/stable/c/546dde823a36d7283dcf46127c2f3d093443860f
- https://git.kernel.org/stable/c/5c63e2ed840c85e27172ab78e7db3ac77fba281b
- https://git.kernel.org/stable/c/6ee52d3af2a1bf70349cf3f860933c8d221e229a
- https://git.kernel.org/stable/c/7077ec953996acc04b49d1dfc43df1c1a2a74395
- https://git.kernel.org/stable/c/b7631982fb65dd355acd18e62b384bc8125e9c44