Host-kernel overwrite via mutable command-size TOCTOU
Published Jul 10, 2026 · Updated Jul 10, 2026
TOCTOU in Imagination Technologies Graphics DDK allows local users in a Host VM to overwrite host-kernel memory via GPU commands. The rgxfw_hwperf_ufo() firmware function checks psCmdHeader->ui32CmdSize, then re-reads the mutable field before use, so a malicious driver can enlarge the command after validation. Kernel software must already be installed and running inside the Host VM; successful abuse crosses the VM boundary and corrupts host-kernel memory.
Summary
What happened
TOCTOU in Imagination Technologies Graphics DDK allows local users in a Host VM to overwrite host-kernel memory via GPU commands. The rgxfw_hwperf_ufo() firmware function checks psCmdHeader->ui32CmdSize, then re-reads the mutable field before use, so a malicious driver can enlarge the command after validation. Kernel software must already be installed and running inside the Host VM; successful abuse crosses the VM boundary and corrupts host-kernel memory.
The record
- CVE
- CVE-2026-45203
- Published
- Jul 10, 2026
- Updated
- Jul 10, 2026
- Vendor
- Imagination Technologies
- Product
- Graphics DDK
- Classifications
- CWE-367, CAPEC-480, T1611
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 2026CVE publishedPublication date reported by the CVE source.
- Jul 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=1.18 RTM2
- Affected versionversion=23.2 RTM2
- Affected versionversion=24.2 RTM2
- Affected versionversion=25.1 RTM2 <=25.3 RTM
- Affected versionversion=26.1 RTM1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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