Recently, a serious security vulnerability numbered CVE-2025-10263 was officially disclosed and was confirmed to affect multiple Arm architecture CPU cores, covering the latest and early generations of products. The vulnerability, rated "Critical," allows an attacker to exploit the timing conditions during specific memory permission changes to achieve local privilege escalation on the affected system.
According to public information, the root cause of the problem is that when performing a TLB invalidation (TLBI) operation, the completion of the relevant memory access is not strictly guaranteed by the completion of the TLBI.
In some scenarios, this behavior may lead to illegal writes to resources that should be owned by a higher exception level (such as a higher privilege level), thus becoming a means for attackers to escalate privileges.
Although the vulnerability was assigned a number in 2025, it was not officially publicly disclosed until June 2026.
Arm gave a fairly extensive list of affected cores in its security advisory.
These include the latest C1-Ultra and C1-Premium, as well as the previous Neoverse V3, V3AE, V2, V1, N2, N1 and other series of cores for servers and data centers.
At the same time, a large number of Cortex series for high-performance mobile and client devices are also affected, including Cortex-X925, Cortex-X4, Cortex-X3, Cortex-X2, Cortex-X1 and X1C, as well as models such as Cortex-A710, Cortex-A78, A78AE, A78C, Cortex-A77, Cortex-A76 and A76AE.
In response to this problem, the software-level mitigation suggestions given by Arm are: Any software that performs TLB invalidation operations applicable to first-level or first-level plus second-level page table information must perform an additional TLBI operation and cooperate with DSB (Data Synchronization Barrier, data synchronization barrier) to ensure that the relevant memory access is completed correctly before permissions are changed.
The corresponding technical details and recommended mitigation solutions have been documented in the security advisory published by Arm.
The Linux community has responded immediately and provided patches to the kernel to implement the above mitigation measures.
Developers from Arm submitted a series of patches to the Linux kernel mailing list today to reduce the risk of vulnerability exploitation by adjusting the relevant code paths to ensure that the necessary TLBI and DSB are added when executing TLB failures in affected scenarios.
The patch has been submitted to the mainline kernel and is expected to be released to users through major distribution updates.
In addition to Arm’s officially listed processors, NVIDIA also confirmed that its latest Olympus cores are also affected by CVE-2025-10263.
NVIDIA pointed out in another patch submitted to the Linux kernel that the Olympus kernel used in its new generation of NVIDIA Vera CPUs has the same issue, and introduced corresponding mitigation measures through subsequent patches to be consistent with upstream universal fixes.
In terms of actual risks, since this vulnerability can realize writing operations to high-privilege resources under certain conditions, and can theoretically provide attackers with a way to escalate local privileges, it is not surprising that it is rated as "critical".
However, there are currently no large-scale actual use cases that have been publicly reported. The industry is mainly focused on completing repairs at the kernel and system software levels as soon as possible to prevent possible subsequent attack scenarios.
For Linux users and server operators, the most critical action at the moment is to pay attention to the kernel updates that will be provided by major distributions and complete the upgrade deployment as soon as possible.
Prior to this, cloud service providers, large data centers, and equipment manufacturers based on the affected Arm platform also need to evaluate the processor models and workload scenarios used by their own hardware, and promptly follow up on the mitigation recommendations issued by the Arm and Linux communities.