{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80552", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.766Z", "datePublished": "2026-08-26T14:37:21.178Z", "dateUpdated": "2026-10-16T19:26:26.482Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-27T12:40:12.535Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Ensure index for read/write regions are within range\n\nThe introduction of the capability chain rightly clamped the\nregion indexes to the range of the capabilities itself, but\nneglected to do so for the existing read/write regions which\nshould also be enforced." } ], "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 - The flaw is reached only via local VFIO mediated-device syscalls (read/write on a vfio-ccw device fd and VFIO_DEVICE_GET_REGION_INFO ioctl); vfio-ccw has no network, Bluetooth, or physical-bus entry point.\nAC:L - An attacker with an open vfio-ccw fd can deterministically supply crafted file offsets encoding out-of-range region indexes to read/write/ioctl handlers, or race close/teardown against region access, without depending on uncontrollable kernel layout or rare timing.\nPR:L - Exploitation requires an opened vfio-ccw mdev device fd (typical QEMU/libvirt VM operator or delegated /dev/vfio holder on IBM Z passthrough); mdev creation is admin setup, but triggering the OOB paths needs only that delegated VFIO client, not init-namespace root.\nUI:N - No separate victim action is required beyond the attacker (or their QEMU process) issuing crafted VFIO read/write/ioctl calls on an already-assigned passthrough device; no mount, click, or other user cooperation is needed at trigger time.\nS:C - On IBM Z/LinuxONE, vfio-ccw exists to pass DASD/CCW subchannels into KVM guests; OOB region indexing in host read/write/ioctl corrupts hypervisor kernel memory outside the guest VM security boundary, enabling cross-tenant host compromise.\nC:H - Missing bounds checks and array_index_nospec on region[i] let out-of-range indexes make copy_to_user read from adjacent kernel heap/metadata beyond the region array, providing arbitrary kernel memory disclosure primitives.\nI:H - Out-of-range region indexes route copy_from_user writes to wrong kernel objects (cmd_region, schib_region, crw_region, or adjacent heap), enabling heap corruption and exploitable arbitrary kernel write or control-flow hijack.\nA:H - Out-of-bounds access to freed or invalid region metadata during concurrent device close, or corrupting vfio_ccw_private adjacent structures, can immediately oops or panic the host kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/s390/cio/vfio_ccw_async.c", "drivers/s390/cio/vfio_ccw_chp.c", "drivers/s390/cio/vfio_ccw_ops.c" ], "versions": [ { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "3acbedf5c0b8e0971f0de423c05cc02bbf6ddb99", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "d3b1e38404b22df5a1f93019f2bb656feaad5ae3", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "79ea5e0c4c8a9842ae85f45062d947b3297dfc07", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "d597fa1273802941c7801202135976fecc29672b", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "649badf3a2fd8929e40198603a2cb21b74c21700", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "988d9b5be3c2c4baf9457ce8e11b477e13eb9fcf", "status": "affected", "versionType": "git" }, { "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "lessThan": "9f5f9a78fedc45bc29d6a0a64e3a3472361afae5", "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/s390/cio/vfio_ccw_async.c", "drivers/s390/cio/vfio_ccw_chp.c", "drivers/s390/cio/vfio_ccw_ops.c" ], "versions": [ { "version": "5.2", "status": "affected" }, { "version": "0", "lessThan": "5.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.218", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.153", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.105", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.46", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.10", "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": "5.2", "versionEndExcluding": "5.15.218" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.6.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.12.105" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.18.46" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.1.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3acbedf5c0b8e0971f0de423c05cc02bbf6ddb99" }, { "url": "https://git.kernel.org/stable/c/d3b1e38404b22df5a1f93019f2bb656feaad5ae3" }, { "url": "https://git.kernel.org/stable/c/79ea5e0c4c8a9842ae85f45062d947b3297dfc07" }, { "url": "https://git.kernel.org/stable/c/d597fa1273802941c7801202135976fecc29672b" }, { "url": "https://git.kernel.org/stable/c/649badf3a2fd8929e40198603a2cb21b74c21700" }, { "url": "https://git.kernel.org/stable/c/988d9b5be3c2c4baf9457ce8e11b477e13eb9fcf" }, { "url": "https://git.kernel.org/stable/c/9f5f9a78fedc45bc29d6a0a64e3a3472361afae5" } ], "title": "s390/vfio_ccw: Ensure index for read/write regions are within range", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-80552", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:17:15.526707Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": 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