{"id":"CVE-2026-64524","title":"drm/hyperv: validate resolution_count and fix WIN8 fallback","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/hyperv: validate resolution_count and fix WIN8 fallback\n\nA SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past\nthe supported_resolution[SYNTHVID_MAX_…","severity":"high","cvss":7.7,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 96f7de3172d4aa878b7f87173b2b3507c350fcd6","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < bc573752f3dac0d1ab8df7078c1851bc76717653","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 1fb565b77b8f44afabb02de6310065f109d89e94","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < a321c908f2eeea01539668eb270d074d9b88e490","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 9c698b2c43c2667c34f5336bf46ad5786216ac2a","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 8a114b25b5521eae451b13bce98ae978624962e5","Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 13d33b9ef67066c77c84273fac5a1d3fde3533d1","Linux 5.14"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:41:39.558295Z"},"published":"2026-07-25","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:39.416Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64524","references":[{"url":"https://git.kernel.org/stable/c/96f7de3172d4aa878b7f87173b2b3507c350fcd6"},{"url":"https://git.kernel.org/stable/c/bc573752f3dac0d1ab8df7078c1851bc76717653"},{"url":"https://git.kernel.org/stable/c/1fb565b77b8f44afabb02de6310065f109d89e94"},{"url":"https://git.kernel.org/stable/c/a321c908f2eeea01539668eb270d074d9b88e490"},{"url":"https://git.kernel.org/stable/c/9c698b2c43c2667c34f5336bf46ad5786216ac2a"},{"url":"https://git.kernel.org/stable/c/8a114b25b5521eae451b13bce98ae978624962e5"},{"url":"https://git.kernel.org/stable/c/13d33b9ef67066c77c84273fac5a1d3fde3533d1"}],"tags":["cve.org"],"epss":0.00142,"epssPercentile":0.03118,"ingestedAt":"2026-10-16T17:24:46.825Z","slug":"CVE-2026-64524","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndrm/hyperv: validate resolution_count and fix WIN8 fallback\n\nA SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past\nthe supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the\nparse loop. Bound resolution_count against the array size, folded\ninto the existing zero-check.\n\nWhen the WIN10 resolution probe fails, the caller in\nhyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated,\nwhich sets mode_config.max_width / max_height to 0 and makes\ndrm_internal_framebuffer_create() reject every userspace framebuffer\nwith -EINVAL. The pre-WIN10 branch had the same gap for\npreferred_width / preferred_height. Use a single post-probe fallback\nguarded by screen_width_max == 0 so both paths converge on the WIN8\ndefaults.\n\n## Affected\n\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 96f7de3172d4aa878b7f87173b2b3507c350fcd6`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < bc573752f3dac0d1ab8df7078c1851bc76717653`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 1fb565b77b8f44afabb02de6310065f109d89e94`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < a321c908f2eeea01539668eb270d074d9b88e490`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 9c698b2c43c2667c34f5336bf46ad5786216ac2a`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 8a114b25b5521eae451b13bce98ae978624962e5`\n- `Linux >= 76c56a5affeba1e163b66b9d8cc192e6154466f0 < 13d33b9ef67066c77c84273fac5a1d3fde3533d1`\n- `Linux 5.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":42.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}