{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74703","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.927Z","datePublished":"2026-08-22T15:33:02.872Z","dateUpdated":"2026-08-25T05:41:46.287Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:41:46.287Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-scsi: Validate T10 PI scatterlist counts\n\nWhen T10 PI is negotiated, vhost-scsi splits protection bytes from\nthe data iterator before mapping the request scatterlists. A malformed\nrequest can claim protection bytes that cover or exceed the full payload\nlength. The former leaves no data bytes to map, while the latter\nunderflows exp_data_len before advancing the iterator. Both cases can let\na zero data SGL count reach sg_alloc_table_chained(), which triggers\nBUG_ON(!nents).\n\nReject protection lengths that cover or exceed the payload before\nsubtracting prot_bytes and advancing the iterator. Also propagate\nnegative errors from the protection SGL calculation before calling the\nallocator, matching the data SGL path."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - A malicious KVM guest reaches vhost_scsi_handle_vq() by kicking the virtio-scsi I/O virtqueue; vhost_get_vq_desc() and copy_from_iter_full() pull a guest-controlled virtio_scsi_cmd_req_pi header into the host kernel, not via any network-facing protocol.\nAC:L - With VIRTIO_SCSI_F_T10_PI negotiated, the guest fully controls pi_bytesout/pi_bytesin and descriptor payload sizes; setting protection bytes to cover or exceed the payload deterministically leaves zero data SGL entries and hits BUG_ON(!nents) without races or uncontrollable memory layout.\nPR:N - No host root or capabilities are required; a malicious VM tenant only needs code execution inside a guest with an active virtio-scsi/vhost-scsi endpoint (standard QEMU/KVM+LIO passthrough), matching other guest-to-host virtio/KVM CNA scores for cloud multi-tenant hosts.\nUI:N - No separate victim action is needed; the attacker submits crafted virtio-scsi requests and kicks the virtqueue from their own guest workload without requiring a host administrator or another user to mount storage or perform any interactive step.\nS:C - Guest-supplied virtio-scsi T10 PI requests trigger BUG_ON(!nents) in host sg_alloc_table_chained() during vhost_scsi_mapal(), panicking the physical host kernel and crossing the KVM guest-to-host virtualization security boundary.\nC:N - The failure mode is an explicit BUG_ON(!nents) on zero scatterlist count; there is no demonstrated out-of-bounds read, use-after-free, or other memory corruption before the panic that could disclose host kernel data.\nI:N - No guest-controlled host memory write or control-flow hijack occurs; the host kernel aborts via BUG_ON before target_submit_prep(), and the bug is invalid scatterlist accounting rather than exploitable heap corruption.\nA:H - BUG_ON(!nents) in sg_alloc_table_chained() provokes a host kernel oops/panic in the vhost worker during guest virtio-scsi I/O, denying availability of the hypervisor and all co-resident VMs; the attack is reliably repeatable with crafted PI headers."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/scsi.c"],"versions":[{"version":"bca939d5bcd00d6faea99c47eafd60bed573ef03","lessThan":"2417a498cf3fe64d06faf87e236eda98dd4f04e0","status":"affected","versionType":"git"},{"version":"bca939d5bcd00d6faea99c47eafd60bed573ef03","lessThan":"f8fe3f8d342da750dd10361bf66009fd3072926b","status":"affected","versionType":"git"},{"version":"bca939d5bcd00d6faea99c47eafd60bed573ef03","lessThan":"d876c493fc4b811941bfeb4c80beb2dfc4bf025e","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/vhost/scsi.c"],"versions":[{"version":"6.15","status":"affected"},{"version":"0","lessThan":"6.15","status":"unaffected","versionType":"semver"},{"version":"6.18.45","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.9","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.15","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/2417a498cf3fe64d06faf87e236eda98dd4f04e0"},{"url":"https://git.kernel.org/stable/c/f8fe3f8d342da750dd10361bf66009fd3072926b"},{"url":"https://git.kernel.org/stable/c/d876c493fc4b811941bfeb4c80beb2dfc4bf025e"}],"title":"vhost-scsi: Validate T10 PI scatterlist counts","x_generator":{"engine":"bippy-1.2.0"}}}}