{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64524", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.794Z", "datePublished": "2026-07-25T09:20:48.193Z", "dateUpdated": "2026-08-05T12:42:37.752Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:42:37.752Z" }, "descriptions": [ { "lang": "en", "value": "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_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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The malicious resolution response must originate from the local Hyper-V synthetic-video backend over VMBus; it is not reachable through a network protocol or guest userspace ioctl.\nAC:L - The backend can deterministically trigger the flaw by returning a resolution_count from 65 through 255 during the normal WIN10+ probe or resume exchange, without a race or unpredictable condition.\nPR:N - The guest accepts the VMBus response without authentication, capability checks, or guest credentials; a malicious or compromised backend requires no privileges within the vulnerable guest.\nUI:N - The response is processed automatically during device probing or resume, without any victim action.\nS:U - The vulnerable parser and the affected DRM and kernel resources are within the same guest-kernel security authority; this does not produce a guest-to-host escape.\nC:H - A count of 255 causes 191 additional four-byte entries to be read beyond the declared array, substantially exceeding a small bounded disclosure and allowing out-of-bounds kernel data to influence observable display state.\nI:N - The invalid accesses are reads, and their results are written only to the intended resolution fields; no out-of-bounds write, use-after-free, or control-flow corruption was found.\nA:H - Bounds-instrumented hardened kernels can oops when index 64 is reached, while a failed or malformed resolution probe can leave zero maximum dimensions and make every userspace framebuffer creation fail." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpu/drm/hyperv/hyperv_drm_proto.c" ], "versions": [ { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "96f7de3172d4aa878b7f87173b2b3507c350fcd6", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "bc573752f3dac0d1ab8df7078c1851bc76717653", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "1fb565b77b8f44afabb02de6310065f109d89e94", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "a321c908f2eeea01539668eb270d074d9b88e490", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "9c698b2c43c2667c34f5336bf46ad5786216ac2a", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "8a114b25b5521eae451b13bce98ae978624962e5", "status": "affected", "versionType": "git" }, { "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0", "lessThan": "13d33b9ef67066c77c84273fac5a1d3fde3533d1", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpu/drm/hyperv/hyperv_drm_proto.c" ], "versions": [ { "version": "5.14", "status": "affected" }, { "version": "0", "lessThan": "5.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.12.93" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.18.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.0.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.1" } ] } ] } ], "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" } ], "title": "drm/hyperv: validate resolution_count and fix WIN8 fallback", "x_generator": { "engine": "bippy-1.2.0" } } } }