CVE-2026-99177

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99177", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.399Z", "datePublished": "2026-10-28T10:35:31.315Z", "dateUpdated": "2026-10-31T12:44:45.294Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-31T12:44:45.294Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Fix page dirtying in sev_gmem_post_populate()\n\nset_page_dirty() requires that the caller holds some kind of lock to\nensure that the page's mapping does not concurrently go away.\nThat is not the case for a random page we got from get_user_pages_fast(),\nso use set_page_dirty_lock().\n\n[sean: tag for stable]"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - Local ioctl(KVM_MEMORY_ENCRYPT_OP) follows kvm_vm_ioctl() \u2192 sev_mem_enc_ioctl() \u2192 snp_launch_update() \u2192 kvm_gmem_populate() \u2192 patched sev_gmem_post_populate(); the triggering CPUID page comes from the ioctl's userspace uaddr, not a network peer or guest.\nAC:L - The caller can supply a CPUID page that makes SEV_CMD_SNP_LAUNCH_UPDATE return SEV_RET_INVALID_PARAM and concurrently tear down its file-backed source mapping; the same attacker controls both sides of the set_page_dirty() race.\nPR:L - kvm_vm_ioctl() requires a same-mm VM fd and __sev_issue_cmd() requires a valid /dev/sev fd, but sev_mem_enc_ioctl() and snp_launch_update() perform no capability check; an unprivileged VMM account granted those device fds suffices.\nUI:N - The attacker creates and initializes the SNP VM, submits the rejected CPUID page, and races teardown of that page's mapping without any action by another user.\nS:U - The UAF occurs in the host kernel while servicing the host VMM's launch ioctl; it is not a guest-to-host escape because the guest has not begun executing on this pre-launch failure path.\nC:H - folio_mark_dirty() can invoke mapping->a_ops->dirty_folio through a freed inode-embedded address_space; grooming the stale object and exploiting the resulting kernel control-flow or mapping-state corruption can provide arbitrary host-kernel memory access.\nI:H - For buffer-backed pages, the stale callback can enter block_dirty_folio(), modify freed mapping locks and buffer state, then call __folio_mark_dirty() and __mark_inode_dirty() through reused objects, providing exploitable UAF writes and potential kernel code execution.\nA:H - The stale dirty_folio callback can dereference freed or poisoned a_ops, spinlocks, buffer heads, or host-inode state, causing a host kernel oops or panic."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/svm/sev.c"], "versions": [{"version": "97cd21d57e9bd2da79845178d9250cfd19289cd4", "lessThan": "184382f9852d433af21de96c334ecf43b8414ed8", "status": "affected", "versionType": "git"}, {"version": "97cd21d57e9bd2da79845178d9250cfd19289cd4", "lessThan": "97818b2fa7082e940ddd36dab12a68615300e798", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/svm/sev.c"], "versions": [{"version": "7.2", "status": "affected"}, {"version": "0", "lessThan": "7.2", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.13", "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": "7.2", "versionEndExcluding": "7.2.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/184382f9852d433af21de96c334ecf43b8414ed8"}, {"url": "https://git.kernel.org/stable/c/97818b2fa7082e940ddd36dab12a68615300e798"}], "title": "KVM: SEV: Fix page dirtying in sev_gmem_post_populate()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/x86/kvm/svm/sev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "184382f9852d433af21de96c334ecf43b8414ed8", "status": "affected", "version": "97cd21d57e9bd2da79845178d9250cfd19289cd4", "versionType": "git"}, {"lessThan": "97818b2fa7082e940ddd36dab12a68615300e798", "status": "affected", "version": "97cd21d57e9bd2da79845178d9250cfd19289cd4", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/x86/kvm/svm/sev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.2"}, {"lessThan": "7.2", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.13", "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\nKVM: SEV: Fix page dirtying in sev_gmem_post_populate()\n\nset_page_dirty() requires that the caller holds some kind of lock to\nensure that the page's mapping does not concurrently go away.\nThat is not the case for a random page we got from get_user_pages_fast(),\nso use set_page_dirty_lock().\n\n[sean: tag for stable]"}], "id": "CVE-2026-99177", "lastModified": "2026-10-31T13:17:58.880", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-10-28T11:17:38.397", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/184382f9852d433af21de96c334ecf43b8414ed8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/97818b2fa7082e940ddd36dab12a68615300e798"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: kernel: Denial of Service via improper page dirtying locking in KVM SEV", "id": "2562668", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2562668"}, "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-413", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nKVM: SEV: Fix page dirtying in sev_gmem_post_populate()\nset_page_dirty() requires that the caller holds some kind of lock to\nensure that the page's mapping does not concurrently go away.\nThat is not the case for a random page we got from get_user_pages_fast(),\nso use set_page_dirty_lock().\n[sean: tag for stable]", "A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem. This vulnerability may lead to a Denial of Service (DoS) due to improper locking when marking guest memory pages as modified during AMD Secure Encrypted Virtualization (SEV) operations. A local user with permissions to manage virtual machines could trigger a race condition where memory mappings concurrently disappear, resulting in memory corruption and a system crash."], "name": "CVE-2026-99177", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-10", "product_name": "Red Hat OpenShift Container Platform 5"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 5"}], "public_date": "2026-10-28T10:35:31Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99177\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99177\nhttps://git.kernel.org/stable/c/184382f9852d433af21de96c334ecf43b8414ed8\nhttps://git.kernel.org/stable/c/97818b2fa7082e940ddd36dab12a68615300e798"], "statement": "This vulnerability is rated as Moderate impact for Red Hat because exploitation requires local privileges to manage virtual machines on AMD hardware utilizing Secure Encrypted Virtualization (SEV). In standard Red Hat Enterprise Linux environments, unprivileged users do not have direct access to KVM device interfaces, limiting exposure to authorized hypervisor operators. Furthermore, the potential impact is confined to host denial of service through a system crash, without enabling data leakage or integrity compromise.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[97cd21d57e9bd2da79845178d9250cfd19289cd4,184382f9852d433af21de96c334ecf43b8414ed8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[97cd21d57e9bd2da79845178d9250cfd19289cd4,97818b2fa7082e940ddd36dab12a68615300e798)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "7.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.13,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[97cd21d57e9bd2da79845178d9250cfd19289cd4,184382f9852d433af21de96c334ecf43b8414ed8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[97cd21d57e9bd2da79845178d9250cfd19289cd4,97818b2fa7082e940ddd36dab12a68615300e798)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"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": "7.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.13,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-10-28T13:00:15.530300+00:00", "updated": "2026-11-03T02:00:08.610674+00:00", "vendors": ["linux", "linux$PRODUCT$linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-413"]}