Multiple security vulnerabilities were found in the Linux kernel used by Ubuntu, including a specific issue affecting some Arm processors. This particular issue allows a local attacker to write to memory after access permission is revoked, potentially bypassing protections or gaining higher privileges. Overall, many other security flaws affecting numerous subsystems were also fixed in this update.
Published 21/9/2026, 1:04:36 pmVerified 22/9/2026, 3:22:13 amRevision 1
In plain language
What this advisory means
Multiple security vulnerabilities were found in the Linux kernel used by Ubuntu, including a specific issue affecting some Arm processors. This particular issue allows a local attacker to write to memory after access permission is revoked, potentially bypassing protections or gaining higher privileges. Overall, many other security flaws affecting numerous subsystems were also fixed in this update.
Technical explanation
How the issue affects the environment
In some Arm processors, a broadcast translation lookaside buffer (TLB) invalidation could complete before the memory writes through the invalidated translation were globally observed. This timing discrepancy allows a local attacker to write to memory after permission to do so has been revoked, thus bypassing memory protection mechanisms or escalating privileges (CVE-2025-10263). Additionally, multiple security issues across various Linux kernel subsystems—including ARM64 and ARM32 architectures, x86, RISC-V, cryptographic APIs, device drivers, network stacks, filesystems, and more—were addressed to prevent potential system compromises.
Operational impact
Why teams should care
Without remediation, systems running the vulnerable Linux kernel could be compromised by local attackers, allowing them to bypass memory protections or escalate privileges. This poses risks of unauthorized data access, system instability, or full system compromise. Organizations relying on Ubuntu Linux in enterprise or cloud environments should apply updates promptly to mitigate these risks.
Immediate action
Update the Linux kernel to version 7.0.0-1013.13 or later as provided by Ubuntu for your system, and then reboot the computer to apply all necessary changes. After updating, recompile and reinstall any third-party kernel modules due to ABI changes.
Affected and fixed releases
Affected versionsConfirm in the official vendor advisory
Fixed versions7.0.0-1013.13
Temporary risk reduction
The official source does not specify any workaround; applying the update is required to address the issues.
Evidence and validation checklist
The advisory directly states the discovery of Arm processor TLB invalidation issue (CVE-2025-10263).
It notes local attacker could bypass memory protections or escalate privileges.
Linux kernel security flaws affect numerous subsystems listed in the advisory.
Update instructions specify kernel package version 7.0.0-1013.13 as remediation.
Reboot and recompilation instructions indicate changes requiring module rebuilds.
Authoritative reference
Ubuntu Security Notices
QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.
