{"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": "2026-08-27T12:40:12.535Z"}, "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."}]}], 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"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": 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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/s390/cio/vfio_ccw_async.c", "drivers/s390/cio/vfio_ccw_chp.c", "drivers/s390/cio/vfio_ccw_ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3acbedf5c0b8e0971f0de423c05cc02bbf6ddb99", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "d3b1e38404b22df5a1f93019f2bb656feaad5ae3", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "79ea5e0c4c8a9842ae85f45062d947b3297dfc07", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "d597fa1273802941c7801202135976fecc29672b", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "649badf3a2fd8929e40198603a2cb21b74c21700", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "988d9b5be3c2c4baf9457ce8e11b477e13eb9fcf", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}, {"lessThan": "9f5f9a78fedc45bc29d6a0a64e3a3472361afae5", "status": "affected", "version": "db8e5d17ac03a65e2e0ee0ba50bf61a99741d871", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/s390/cio/vfio_ccw_async.c", "drivers/s390/cio/vfio_ccw_chp.c", "drivers/s390/cio/vfio_ccw_ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.2"}, {"lessThan": "5.2", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.218", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.184", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.153", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.105", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.46", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.10", "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\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."}], "id": "CVE-2026-80552", "lastModified": "2026-08-27T13:18:39.870", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-26T15:17:09.723", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3acbedf5c0b8e0971f0de423c05cc02bbf6ddb99"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/649badf3a2fd8929e40198603a2cb21b74c21700"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/79ea5e0c4c8a9842ae85f45062d947b3297dfc07"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/988d9b5be3c2c4baf9457ce8e11b477e13eb9fcf"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9f5f9a78fedc45bc29d6a0a64e3a3472361afae5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d3b1e38404b22df5a1f93019f2bb656feaad5ae3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d597fa1273802941c7801202135976fecc29672b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: s390/vfio_ccw: Ensure index for read/write regions are within range", "id": "2524509", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524509"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ns390/vfio_ccw: Ensure index for read/write regions are within range\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.", "A flaw was found in the `s390/vfio_ccw` component of the Linux kernel. This vulnerability occurs because the system fails to properly validate index ranges for read/write operations on existing regions. This oversight could allow an attacker to perform out-of-bounds memory access, potentially leading to information disclosure or system instability."], "name": "CVE-2026-80552", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "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": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-26T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-80552\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80552\nhttps://lore.kernel.org/linux-cve-announce/2026082608-CVE-2026-80552-feb6@gregkh/T"], "threat_severity": "Moderate"}