CVE-2026-74703

{"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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/vhost/scsi.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2417a498cf3fe64d06faf87e236eda98dd4f04e0", "status": "affected", "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03", "versionType": "git"}, {"lessThan": "f8fe3f8d342da750dd10361bf66009fd3072926b", "status": "affected", "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03", "versionType": "git"}, {"lessThan": "d876c493fc4b811941bfeb4c80beb2dfc4bf025e", "status": "affected", "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/vhost/scsi.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"lessThan": "6.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nvhost-scsi: Validar los recuentos de scatterlist de T10 PI\n\nCuando se negocia T10 PI, vhost-scsi divide los bytes de protecci\u00f3n del iterador de datos antes de mapear las scatterlists de la solicitud. Una solicitud malformada puede reclamar bytes de protecci\u00f3n que cubren o exceden la longitud total de la carga \u00fatil. El primero no deja bytes de datos para mapear, mientras que el segundo provoca un desbordamiento negativo en exp_data_len antes de avanzar el iterador. Ambos casos pueden permitir que un recuento SGL de datos cero llegue a sg_alloc_table_chained(), lo que activa BUG_ON(!nents).\n\nRechazar longitudes de protecci\u00f3n que cubren o exceden la carga \u00fatil antes de restar prot_bytes y avanzar el iterador. Tambi\u00e9n propagar errores negativos del c\u00e1lculo SGL de protecci\u00f3n antes de llamar al asignador, coincidiendo con la ruta SGL de datos."}], "id": "CVE-2026-74703", "lastModified": "2026-10-14T13:10:00.187", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.5, "impactScore": 4.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-22T16:16:44.983", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2417a498cf3fe64d06faf87e236eda98dd4f04e0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d876c493fc4b811941bfeb4c80beb2dfc4bf025e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f8fe3f8d342da750dd10361bf66009fd3072926b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: vhost-scsi: Validate T10 PI scatterlist counts", "id": "2521398", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521398"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-191", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nvhost-scsi: Validate T10 PI scatterlist counts\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).\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.", "A flaw was found in the Linux kernel's `vhost-scsi` component. When T10 Protection Information (PI) is negotiated, a remote attacker could send a specially crafted request with malformed scatterlist counts. This could lead to an invalid memory allocation operation, triggering a kernel panic and resulting in a Denial of Service (DoS) for the affected system."], "name": "CVE-2026-74703", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74703\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74703\nhttps://lore.kernel.org/linux-cve-announce/2026082236-CVE-2026-74703-dcf0@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bca939d5bcd00d6faea99c47eafd60bed573ef03,2417a498cf3fe64d06faf87e236eda98dd4f04e0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bca939d5bcd00d6faea99c47eafd60bed573ef03,f8fe3f8d342da750dd10361bf66009fd3072926b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bca939d5bcd00d6faea99c47eafd60bed573ef03,d876c493fc4b811941bfeb4c80beb2dfc4bf025e)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.45,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-22T18:15:03.690262+00:00", "updated": "2026-08-25T17:15:05.689679+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}