CVE-2026-52959

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-52959", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.373Z", "datePublished": "2026-06-24T16:28:40.391Z", "dateUpdated": "2026-08-05T12:32:09.604Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:32:09.604Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirt: sev-guest: Do not use host-controlled page order in cleanup path\n\nWhen issuing an extended guest request (SVM_VMGEXIT_EXT_GUEST_REQUEST),\nget_ext_report() allocates a buffer to retrieve a certificate blob from the\nhost, keeping track of its size in report_req->certs_len.\n\nHowever, the host may return SNP_GUEST_VMM_ERR_INVALID_LEN, indicating\nan invalid buffer size, as well as the expected length of such buffer.\nget_ext_report() subsequently updates report_req->certs_len with the\nhost-controlled value, and cleans up the buffer by computing a page order\nfrom such value. This is incorrect, as the host-provided length may not\nmatch the page order of the original allocation, potentially resulting\nin corruption in the page allocator.\n\nFix this by using alloc_pages_exact() instead, and reusing @npages to\ncompute the size passed to free_pages_exact(). For consistency, also\nuse @npages to compute the size when allocating the pages, even though\nthis last change has no functional effect."}], "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 - The vulnerable path is reached through local guest interfaces, primarily the /dev/sev-guest SNP_GET_EXT_REPORT ioctl and the TSM configfs report path. It is not directly reachable by network packets, adjacent protocols, or physical device insertion.\nAC:L - There is no race or fragile timing requirement; the caller can request an undersized certificate buffer and the VMM can deterministically return INVALID_LEN with a mismatched npages value. The resulting wrong-order free occurs synchronously in cleanup.\nPR:L - The driver performs no capable() or namespace privilege check before dispatching SNP_GET_EXT_REPORT; exploitation only requires access to the local attestation interface. Because device-node policy may grant non-root attestation access, the higher-severity low-privilege value is appropriate.\nUI:N - No victim human action is required once a local process or attestation agent issues the request. The corrupted cleanup path is triggered automatically by the VMM response.\nS:U - The corrupted memory is guest kernel page-allocator state governed by the vulnerable guest kernel itself. This is best modeled as kernel memory corruption within the same security authority, not a guest-to-host escape.\nC:H - The wrong-order __free_pages() can return unrelated in-use pages to the allocator, creating page aliasing and plausible arbitrary kernel memory disclosure. Under the required overestimate rule, allocator corruption is treated as high confidentiality impact.\nI:H - Freeing more pages than were allocated can let later allocations overlap live kernel objects, providing a plausible write/control-flow corruption primitive. This supports high integrity impact rather than treating the bug as a mere cleanup error.\nA:H - Page allocator corruption can immediately trigger warnings, bad-page detection, oopses, or later kernel crashes. A repeatable local request can therefore cause high availability impact."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/virt/coco/sev-guest/sev-guest.c"], "versions": [{"version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "lessThan": "3f6fb0211b39aaa1b841260681dd02ca6b693ed5", "status": "affected", "versionType": "git"}, {"version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "lessThan": "9e48b4f813d2c3db75d522aa82ab705ce04b7e2d", "status": "affected", "versionType": "git"}, {"version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "lessThan": "23e6a1ca04ae44806439a5a446e62e4d42e80bb4", "status": "affected", "versionType": "git"}, {"version": "0b16521f95c875e79d657cb8d6911c15080dbb80", "status": "affected", "versionType": "git"}, {"version": "6.13.8", "lessThan": "6.14", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/virt/coco/sev-guest/sev-guest.c"], "versions": [{"version": "6.14", "status": "affected"}, {"version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "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": "6.14", "versionEndExcluding": "6.18.33"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.0.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13.8"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3f6fb0211b39aaa1b841260681dd02ca6b693ed5"}, {"url": "https://git.kernel.org/stable/c/9e48b4f813d2c3db75d522aa82ab705ce04b7e2d"}, {"url": "https://git.kernel.org/stable/c/23e6a1ca04ae44806439a5a446e62e4d42e80bb4"}], "title": "virt: sev-guest: Do not use host-controlled page order in cleanup path", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/virt/coco/sev-guest/sev-guest.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3f6fb0211b39aaa1b841260681dd02ca6b693ed5", "status": "affected", "version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "versionType": "git"}, {"lessThan": "9e48b4f813d2c3db75d522aa82ab705ce04b7e2d", "status": "affected", "version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "versionType": "git"}, {"lessThan": "23e6a1ca04ae44806439a5a446e62e4d42e80bb4", "status": "affected", "version": "3e385c0d6ce88ac9916dcf84267bd5855d830748", "versionType": "git"}, {"status": "affected", "version": "0b16521f95c875e79d657cb8d6911c15080dbb80", "versionType": "git"}, {"lessThan": "6.14", "status": "affected", "version": "6.13.8", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/virt/coco/sev-guest/sev-guest.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"lessThan": "6.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.33", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "366CEEDE-ED7E-4CD5-A00F-927D6C249DFD", "versionEndExcluding": "6.14", "versionStartIncluding": "6.13.8", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "BE7C0D1F-F55F-4F22-B63F-5BA6C15B3DC7", "versionEndExcluding": "6.18.33", "versionStartIncluding": "6.14.1", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A13475D2-59BF-4716-94B5-7C1D239A2CF4", "versionEndExcluding": "7.0.10", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:*", "matchCriteriaId": "7DE421BA-0600-4401-A175-73CAB6A6FB4E", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*", "matchCriteriaId": "1759FFB7-531C-41B1-9AE1-FD3D80E0D920", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:*", "matchCriteriaId": "AD948719-8628-4421-A340-1066314BBD4A", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirt: sev-guest: Do not use host-controlled page order in cleanup path\n\nWhen issuing an extended guest request (SVM_VMGEXIT_EXT_GUEST_REQUEST),\nget_ext_report() allocates a buffer to retrieve a certificate blob from the\nhost, keeping track of its size in report_req->certs_len.\n\nHowever, the host may return SNP_GUEST_VMM_ERR_INVALID_LEN, indicating\nan invalid buffer size, as well as the expected length of such buffer.\nget_ext_report() subsequently updates report_req->certs_len with the\nhost-controlled value, and cleans up the buffer by computing a page order\nfrom such value. This is incorrect, as the host-provided length may not\nmatch the page order of the original allocation, potentially resulting\nin corruption in the page allocator.\n\nFix this by using alloc_pages_exact() instead, and reusing @npages to\ncompute the size passed to free_pages_exact(). For consistency, also\nuse @npages to compute the size when allocating the pages, even though\nthis last change has no functional effect."}], "id": "CVE-2026-52959", "lastModified": "2026-07-14T16:28:18.930", "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": "2026-06-24T17:17:06.157", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/23e6a1ca04ae44806439a5a446e62e4d42e80bb4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/3f6fb0211b39aaa1b841260681dd02ca6b693ed5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9e48b4f813d2c3db75d522aa82ab705ce04b7e2d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: virt: sev-guest: Do not use host-controlled page order in cleanup path", "id": "2492280", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2492280"}, "csaw": false, "cwe": "CWE-131", "details": ["A flaw was found in the Linux kernel's Secure Encrypted Virtualization (SEV) guest module. This vulnerability allows a malicious host to provide an invalid buffer size during an extended guest request. This incorrect handling of host-controlled page order during the cleanup process can lead to a mismatch between the allocated and freed buffer sizes, potentially resulting in corruption within the page allocator. This corruption could lead to system instability or a denial of service."], "name": "CVE-2026-52959", "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": "2026-06-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-52959\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-52959\nhttps://lore.kernel.org/linux-cve-announce/2026062436-CVE-2026-52959-1796@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3e385c0d6ce88ac9916dcf84267bd5855d830748,3f6fb0211b39aaa1b841260681dd02ca6b693ed5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3e385c0d6ce88ac9916dcf84267bd5855d830748,9e48b4f813d2c3db75d522aa82ab705ce04b7e2d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3e385c0d6ce88ac9916dcf84267bd5855d830748,23e6a1ca04ae44806439a5a446e62e4d42e80bb4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "0b16521f95c875e79d657cb8d6911c15080dbb80"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.13.8,6.14)"}}], "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": "6.14"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.14)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.33,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.10,7.0.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "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": "2026-06-24T19:15:15.571038+00:00", "updated": "2026-08-13T15:45:03.832010+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}