CVE-2026-64524
Received Received - Intake

Buffer Overflow in Linux Kernel DRM Hyper-V Driver

Publication date: 2026-07-25

Last updated on: 2026-07-25

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: drm/hyperv: validate resolution_count and fix WIN8 fallback A SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past the supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the parse loop. Bound resolution_count against the array size, folded into the existing zero-check. When the WIN10 resolution probe fails, the caller in hyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated, which sets mode_config.max_width / max_height to 0 and makes drm_internal_framebuffer_create() reject every userspace framebuffer with -EINVAL. The pre-WIN10 branch had the same gap for preferred_width / preferred_height. Use a single post-probe fallback guarded by screen_width_max == 0 so both paths converge on the WIN8 defaults.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-07-25
Last Modified
2026-07-25
Generated
2026-07-25
AI Q&A
2026-07-25
EPSS Evaluated
N/A
NVD
CVE-2026-64524
EUVD
EUVD-2026-49036

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in the Linux kernel involves improper validation of resolution_count in the Hyper-V DRM driver. It allows a SYNTHVID_RESOLUTION_RESPONSE with resolution_count exceeding 64 to access an array out of bounds, causing potential memory corruption or crashes. Additionally, a fallback mechanism for WIN8 fails to properly set screen resolution values, leading to invalid framebuffer creation attempts.

Detection Guidance

This vulnerability affects the Linux kernel's DRM driver for Hyper-V. Detection requires checking kernel logs for Hyper-V DRM errors or framebuffer creation failures. Commands like dmesg | grep -i hyperv or journalctl -k | grep -i drm may help identify issues.

Impact Analysis

If exploited, this flaw could cause system instability, crashes, or denial of service on Linux systems running Hyper-V virtual machines. Attackers might trigger memory corruption or prevent proper display functionality by manipulating resolution parameters.

Mitigation Strategies

Update the Linux kernel to the latest patched version. If using Hyper-V, ensure the host and guest kernels are updated. Monitor logs for framebuffer creation errors after applying updates.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-64524. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart