CVE-2026-80724

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80724", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.788Z", "datePublished": "2026-08-28T07:03:08.410Z", "dateUpdated": "2026-10-19T08:43:13.410Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:43:13.410Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nptp: vmclock: prevent read-only mappings from becoming writable\n\nvmclock_miscdev_mmap() rejects writable mappings of the shared vmclock\nABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the\npage read-only and then upgrade it to writable with mprotect(), after\nwhich the guest can corrupt the host-written timekeeping data (sequence\ncounter, UTC time, TSC offset) that the vmclock ABI defines as read-only.\n\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\nupgraded, as i915 does for its read-only objects and as fixed in drm/vc4\n(CVE-2026-68445) and drm/panthor (CVE-2024-53071)."}], "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 local syscalls to open /dev/vmclock0, mmap the shared ABI page read-only, mprotect it writable, and write host-authoritative fields; there is no network, Bluetooth, or physical-device path to vmclock_miscdev_mmap().\nAC:L - Any process that can open the misc device can reliably mmap(PROT_READ), mprotect(PROT_WRITE), and corrupt the page without races, special memory layout, or timing; VM_MAYWRITE left set is the sole missing check and mprotect honors it per mm/mprotect.c.\nPR:L - vmclock_miscdev_open() performs no capability checks; AWS ClockBound documents chmod a+r on /dev/vmclock0 for unprivileged latency-sensitive apps on EC2/Amazon Linux, so a normal tenant user on affected cloud VMs can reach the bug without root or user-namespace admin caps.\nUI:N - The attacker process performs the full open/mmap/mprotect/write sequence itself; no victim mount, click, or other user action is required beyond the attacker already having local shell access.\nS:C - The vmclock ABI page is hypervisor-written shared memory whose seq_count, UTC time, and TSC offset must stay guest-read-only; mprotect bypass lets a guest user corrupt that host-authoritative data, crossing the guest/hypervisor trust boundary rather than staying within guest-kernel scope alone.\nC:H - Unauthorized writes let an attacker race seq_count updates and corrupt in-flight host-populated fields, yielding torn reads of timekeeping data to other guest consumers and potentially exposing transient host-written values that read-only mmap alone would not reliably observe.\nI:H - After mprotect, the attacker gains arbitrary modification of host-written vmclock_abi fields (seq_count, disruption_marker, counter_value, time_sec, flags), breaking integrity of authoritative timekeeping and migration/disruption signaling relied on by guest kernel PTP and userspace ClockBound consumers.\nA:H - Corrupting seq_count, clock_status, or disruption/vm_generation markers can force ETIMEDOUT/-EINVAL in vmclock_get_crosststamp, trigger false migration/disruption handling, and cause latency-sensitive services to withdraw or fail, producing severe availability loss on affected cloud VMs."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/ptp/ptp_vmclock.c"], "versions": [{"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "5b4f2bec7bea6c04084d720d731bedee7caf878d", "status": "affected", "versionType": "git"}, {"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "3f5677d2f817355147337f0453174c7bb0f3b66a", "status": "affected", "versionType": "git"}, {"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "2496e141827102d6af512950057d402a2cfb2bfc", "status": "affected", "versionType": "git"}, {"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "2e596e7814ba38cdc129991058b6c254ed37cb11", "status": "affected", "versionType": "git"}, {"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "0ce59c4148ecd1520c5592a63bb3c8991ee2d326", "status": "affected", "versionType": "git"}, {"version": "20503272422693d793b84f88bf23fe4e955d3a33", "lessThan": "a5edadbae57e2298a56cf7a4e774a027905a331f", "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/ptp/ptp_vmclock.c"], "versions": [{"version": "6.13", "status": "affected"}, {"version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.47", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.11", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.1", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.13", "versionEndExcluding": "6.18.47"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.1.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.2.1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d"}, {"url": "https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a"}, {"url": "https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc"}, {"url": "https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11"}, {"url": "https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326"}, {"url": "https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f"}], "title": "ptp: vmclock: prevent read-only mappings from becoming writable", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/ptp/ptp_vmclock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "5b4f2bec7bea6c04084d720d731bedee7caf878d", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}, {"lessThan": "3f5677d2f817355147337f0453174c7bb0f3b66a", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}, {"lessThan": "2496e141827102d6af512950057d402a2cfb2bfc", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}, {"lessThan": "2e596e7814ba38cdc129991058b6c254ed37cb11", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}, {"lessThan": "0ce59c4148ecd1520c5592a63bb3c8991ee2d326", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}, {"lessThan": "a5edadbae57e2298a56cf7a4e774a027905a331f", "status": "affected", "version": "20503272422693d793b84f88bf23fe4e955d3a33", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/ptp/ptp_vmclock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.13"}, {"lessThan": "6.13", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.47", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.11", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.1", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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\nptp: vmclock: prevent read-only mappings from becoming writable\n\nvmclock_miscdev_mmap() rejects writable mappings of the shared vmclock\nABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the\npage read-only and then upgrade it to writable with mprotect(), after\nwhich the guest can corrupt the host-written timekeeping data (sequence\ncounter, UTC time, TSC offset) that the vmclock ABI defines as read-only.\n\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\nupgraded, as i915 does for its read-only objects and as fixed in drm/vc4\n(CVE-2026-68445) and drm/panthor (CVE-2024-53071)."}], "id": "CVE-2026-80724", "lastModified": "2026-10-19T09:17:09.397", "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": "2026-08-28T08:16:58.210", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: ptp: vmclock: prevent read-only mappings from becoming writable", "id": "2525481", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2525481"}, "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-279", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nptp: vmclock: prevent read-only mappings from becoming writable\nvmclock_miscdev_mmap() rejects writable mappings of the shared vmclock\nABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the\npage read-only and then upgrade it to writable with mprotect(), after\nwhich the guest can corrupt the host-written timekeeping data (sequence\ncounter, UTC time, TSC offset) that the vmclock ABI defines as read-only.\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\nupgraded, as i915 does for its read-only objects and as fixed in drm/vc4\n(CVE-2026-68445) and drm/panthor (CVE-2024-53071).", "A flaw was found in the Linux kernel's vmclock component. This vulnerability allows a guest operating system, through a userspace process, to change a shared memory page from read-only to writable. This occurs because the vmclock_miscdev_mmap() function fails to properly restrict permission upgrades. As a result, the guest can corrupt critical host-written timekeeping data, such as the sequence counter and Coordinated Universal Time (UTC), leading to data integrity issues."], "name": "CVE-2026-80724", "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": "2026-08-28T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-80724\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80724\nhttps://lore.kernel.org/linux-cve-announce/2026082811-CVE-2026-80724-bc86@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[20503272422693d793b84f88bf23fe4e955d3a33,5b4f2bec7bea6c04084d720d731bedee7caf878d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[20503272422693d793b84f88bf23fe4e955d3a33,2496e141827102d6af512950057d402a2cfb2bfc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[20503272422693d793b84f88bf23fe4e955d3a33,2e596e7814ba38cdc129991058b6c254ed37cb11)"}}], "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": "semver", "value": "6.13"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.13)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.47,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.11,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.1,7.3.0)"}}], "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": "2026-08-28T10:30:17.947213+00:00", "updated": "2026-09-01T16:15:04.992963+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}