{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74580","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.918Z","datePublished":"2026-08-21T16:31:54.076Z","dateUpdated":"2026-08-25T05:40:06.380Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:40:06.380Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost: reset the vring metadata cache on vring reconfiguration\n\nvq->meta_iotlb[] caches the vhost_iotlb_map that backs each vring\nmetadata region, and iotlb_access_ok() returns early on a cache hit,\ntaking the hit as proof that the region has already been validated:\n\n\tif (vhost_vq_meta_fetch(vq, addr, len, type))\n\t\treturn true;\n\nThe cache is reset on VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE, on\ndevice IOTLB (re)initialisation and on vq reset, but not when\nVHOST_SET_VRING_ADDR replaces vq->desc, vq->avail and vq->used, nor when\nVHOST_SET_VRING_NUM changes the region sizes.\n\nWith a device IOTLB attached both ioctls are accepted while the vq is\nlive, and neither validates the addresses at ioctl time: vq_access_ok()\nand vq_log_used_access_ok() return true early because the addresses are\nGIOVAs, deferring validation to prefetch time.  Once the cache has been\npopulated that deferred validation no longer runs -- vq_meta_prefetch()\nhits the stale entry and returns true -- and vhost_vq_meta_fetch() keeps\ntranslating through the old mapping as\n\n\tmap->addr + addr - map->start\n\nfor an address the mapping no longer covers.  vhost_copy_to_user() and\nvhost_copy_from_user() consume the result with __copy_to_user() and\n__copy_from_user(), which do not check it either, so a subsequent used\nring update or descriptor fetch accesses memory outside the region the\nIOTLB actually maps.\n\nReset the metadata cache whenever the vring is reconfigured, so the new\naddresses are pushed back through iotlb_access_ok()'s slow path."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires ioctl on /dev/vhost-net or /dev/vhost-vsock (VHOST_SET_OWNER, VHOST_SET_FEATURES with VIRTIO_F_ACCESS_PLATFORM, VHOST_SET_VRING_ADDR, IOTLB updates); although virtio kicks and network I/O trigger the corrupting copies, the stale-cache state is created only through local vhost character-device syscalls, not remote packets.\nAC:L - An attacker who controls the vhost owner process can deterministically populate meta_iotlb via normal virtqueue traffic, issue VHOST_SET_VRING_ADDR with new GIOVAs while the backend is live, then trigger descriptor/used-ring access; no races, special heap layout, or victim timing are required.\nPR:L - No host root is needed: exploitation is performed by the vhost device owner (standard libvirt/QEMU kvm-group account) or, in the highest-impact cloud scenario, an authorized malicious VM tenant whose virtio traffic drives vhost workers after QEMU updates live vring addresses under VIRTIO_F_ACCESS_PLATFORM.\nUI:N - No end-user or administrator action is required beyond routine automated VM operation (virtio I/O, vhost backend attachment, and vring setup) that the attacker or tenant controls directly.\nS:C - Stale IOTLB metadata translation makes the host kernel read/write outside the mapped vring regions in the VMM userspace address space (QEMU), crossing the guest-to-host virtualization boundary—the same escape class as CVE-2025-38074, not mere in-guest kernel impact.\nC:H - vhost_copy_from_user and __vhost_get_user use vhost_vq_meta_fetch's stale map->addr+addr-map->start translation without bounds checks, enabling out-of-bounds reads of adjacent VMM memory during descriptor and avail-ring fetches (arbitrary misdirected kernel reads from host userspace).\nI:H - vhost_copy_to_user and vhost_put_user write used-ring entries through the same stale translation, giving controlled out-of-bounds writes into the VMM process that can corrupt QEMU heap, IOTLB tables, or migration metadata for code-execution primitives.\nA:H - Misdirected __copy_to_user/__copy_from_user against unmapped or invalid VMM addresses can fault the vhost worker (host kernel oops/panic), and corrupting VMM control structures reliably crashes or kills the hypervisor process, terminating the VM."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vhost.c"],"versions":[{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"5224bd37e37d36076a550d99b2aebba33939fd95","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"54617e9119be2eb728ecdd8d977b99c99d4c498a","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"13fa6f32a56a386a82bd7451644c494beed034af","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"cf363a7a02ce132ef1f58084fdb13e1a3b7da7e7","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"6fa3e9b1fe856259555a7e22f3f3082e7827fd9b","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"f1e21108e3ddfcce62f6cad4ebd7b5674543c9e6","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"b70ebe0bba254e093dd5fd4c0c170941ce83eb85","status":"affected","versionType":"git"},{"version":"f889491380582b4ba2981cf0b0d7d6a40fb30ab7","lessThan":"de845981da67a6b049080c87e605130b0c30adc5","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/vhost.c"],"versions":[{"version":"4.11","status":"affected"},{"version":"0","lessThan":"4.11","status":"unaffected","versionType":"semver"},{"version":"5.10.265","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.216","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.183","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.152","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.104","lessThanOrEqual":"6.12.*","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":"4.11","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/5224bd37e37d36076a550d99b2aebba33939fd95"},{"url":"https://git.kernel.org/stable/c/54617e9119be2eb728ecdd8d977b99c99d4c498a"},{"url":"https://git.kernel.org/stable/c/13fa6f32a56a386a82bd7451644c494beed034af"},{"url":"https://git.kernel.org/stable/c/cf363a7a02ce132ef1f58084fdb13e1a3b7da7e7"},{"url":"https://git.kernel.org/stable/c/6fa3e9b1fe856259555a7e22f3f3082e7827fd9b"},{"url":"https://git.kernel.org/stable/c/f1e21108e3ddfcce62f6cad4ebd7b5674543c9e6"},{"url":"https://git.kernel.org/stable/c/b70ebe0bba254e093dd5fd4c0c170941ce83eb85"},{"url":"https://git.kernel.org/stable/c/de845981da67a6b049080c87e605130b0c30adc5"}],"title":"vhost: reset the vring metadata cache on vring reconfiguration","x_generator":{"engine":"bippy-1.2.0"}}}}