Guest privilege escalation via unchecked command size
Published Dec 6, 2025 · Updated Aug 5, 2026
Integer overflow in Linux 4.3 and later affected kernels allows local users to access kernel memory via crafted SVGA3D commands. The vmw_cmd_check function accepts an oversized userspace SVGA3dCmdHeader.size and uses it in buffer-offset arithmetic without enforcing SVGA_CMD_MAX_DATASIZE. Access to the vmwgfx device inside a VMware guest is required; resulting out-of-bounds kernel access can crash the guest or support privilege escalation.
Summary
What happened
Integer overflow in Linux 4.3 and later affected kernels allows local users to access kernel memory via crafted SVGA3D commands. The vmw_cmd_check function accepts an oversized userspace SVGA3dCmdHeader.size and uses it in buffer-offset arithmetic without enforcing SVGA_CMD_MAX_DATASIZE. Access to the vmwgfx device inside a VMware guest is required; resulting out-of-bounds kernel access can crash the guest or support privilege escalation.
The record
- CVE
- CVE-2025-40277
- Published
- Dec 6, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-190, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 6, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=4.3
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <32b415a9dc2c212e809b7ebc2b14bc3fbda2b9af
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <54d458b244893e47bda52ec3943fdfbc8d7d068b
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <5aea2cde03d4247cdcf53f9ab7d0747c9dca1cfc
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <709e5c088f9c99a5cf2c1d1c6ce58f2cca7ab173
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <a3abb54c27b2c393c44362399777ad2f6e1ff17e
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <b5df9e06eed3df6a4f5c6f8453013b0cabb927b4
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <e58559845021c3bad5e094219378b869157fad53
- Affected versionversion=8ce75f8ab9044fe11caaaf2b2c82471023212f9f <f3f3a8eb3f0ba799fae057091d8c67cca12d6fa0
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
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