CVE-2026-45199 Overview
CVE-2026-45199 affects Imagination Technologies GPU drivers and firmware in virtualized environments. Kernel software running inside a Guest Virtual Machine (VM) can post improper commands to the GPU firmware. These commands trigger writes of data outside the Guest's virtualized GPU memory region. An attacker with local access to a Guest VM can leverage this out-of-bounds write to escalate privileges. The vulnerability is classified under [CWE-823] Use of Out-of-range Pointer Offset. It requires local access and low privileges but no user interaction, and impacts confidentiality, integrity, and availability.
Critical Impact
A local attacker with kernel-level code execution in a Guest VM can trigger out-of-bounds writes in host GPU memory, enabling privilege escalation beyond the virtualization boundary.
Affected Products
- Imagination Technologies GPU drivers and firmware (see vendor advisory for specific versions)
- Systems running Guest VMs with virtualized Imagination GPU access
- Deployments relying on GPU virtualization for tenant isolation
Discovery Timeline
- 2026-08-21 - CVE-2026-45199 published to the National Vulnerability Database (NVD)
- 2026-08-26 - Last updated in NVD database
Technical Details for CVE-2026-45199
Vulnerability Analysis
The flaw resides in how the GPU firmware validates command buffers submitted from a Guest VM. Kernel software inside the Guest submits GPU commands through the paravirtualized interface. The firmware fails to properly bound-check pointer offsets embedded within these commands. As a result, malformed commands cause the firmware to write attacker-controlled data outside the Guest's allocated GPU memory region.
Because the GPU firmware executes with privileges higher than the Guest kernel, any successful out-of-bounds write undermines the isolation guarantee of the virtualization layer. The attacker can corrupt host-side structures, adjacent Guest memory, or firmware state. This creates a path from Guest kernel code execution to broader system compromise.
Root Cause
The root cause is improper validation of pointer offsets in GPU command structures processed by the firmware. The firmware treats offsets provided by the Guest as trusted inputs. It uses them to compute destination addresses for data writes without confirming those addresses remain within the Guest's virtualized GPU memory. This matches the [CWE-823] Use of Out-of-range Pointer Offset weakness pattern.
Attack Vector
Exploitation requires local access to a Guest VM with the ability to execute kernel-level code. An attacker who compromises a Guest kernel, or a malicious tenant with kernel privileges in a shared virtualization environment, can craft GPU commands with manipulated offsets. Submitting these commands to the firmware triggers the out-of-bounds write. The attacker then chains the memory corruption into privilege escalation. Refer to the Imagination Technologies GPU Vulnerabilities advisory for firmware-level details.
Detection Methods for CVE-2026-45199
Indicators of Compromise
- Unexpected GPU firmware crashes, resets, or watchdog events on hosts running Guest VMs
- Guest VM kernel logs showing anomalous GPU command submission errors or driver faults
- Host hypervisor logs recording GPU memory access violations tied to specific Guest tenants
Detection Strategies
- Monitor GPU driver and firmware telemetry for out-of-bounds access exceptions and command validation errors
- Correlate Guest VM privilege escalation events with preceding GPU command activity from the same tenant
- Baseline normal GPU command patterns per Guest and alert on anomalous command sequences or offset values
Monitoring Recommendations
- Ingest hypervisor, GPU driver, and Guest kernel logs into a centralized analytics platform for cross-correlation
- Track firmware version and driver version across the fleet to identify unpatched hosts exposed to the vulnerability
- Alert on repeated GPU resets or firmware reload events, which often precede or accompany exploitation attempts
How to Mitigate CVE-2026-45199
Immediate Actions Required
- Inventory all systems using Imagination Technologies GPUs with virtualization enabled and identify Guest VM exposure
- Apply the vendor firmware and driver updates published in the Imagination Technologies GPU Vulnerabilities advisory as soon as they are available
- Restrict Guest VM kernel access to trusted operators until patches are deployed
Patch Information
Imagination Technologies has published guidance for affected GPU drivers and firmware on its GPU driver vulnerabilities page. Administrators should consult the vendor advisory for the exact fixed versions applicable to their GPU model and integrate the updates into standard hypervisor and Guest kernel maintenance windows.
Workarounds
- Disable GPU passthrough or paravirtualized GPU access for Guest VMs that do not require it
- Limit Guest VMs to trusted workloads and enforce strict tenant isolation on shared virtualization hosts
- Monitor GPU command submission for anomalies and terminate Guests exhibiting suspicious firmware interactions
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
