drm/hyperv: validate resolution_count and fix WIN8 fallback
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64524
- 2026-10-03 Alias added: GHSA-2rhv-cg46-xrx8
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
References
Other 7
- https://git.kernel.org/stable/c/96f7de3172d4aa878b7f87173b2b3507c350fcd6
- https://git.kernel.org/stable/c/bc573752f3dac0d1ab8df7078c1851bc76717653
- https://git.kernel.org/stable/c/1fb565b77b8f44afabb02de6310065f109d89e94
- https://git.kernel.org/stable/c/a321c908f2eeea01539668eb270d074d9b88e490
- https://git.kernel.org/stable/c/9c698b2c43c2667c34f5336bf46ad5786216ac2a
- https://git.kernel.org/stable/c/8a114b25b5521eae451b13bce98ae978624962e5
- https://git.kernel.org/stable/c/13d33b9ef67066c77c84273fac5a1d3fde3533d1
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-64524 · CVE Program
- CVE-2026-64524 · NVD
- FIRST EPSS
- GHSA-2rhv-cg46-xrx8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64524 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences