CVE-2026-53360

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-53360", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.400Z", "datePublished": "2026-07-04T11:53:58.657Z", "dateUpdated": "2026-10-19T20:07:44.426Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:35:09.892Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use\n\nAs per the GHCB spec, when using GHCB v2+ require the software scratch area\nto reside in the GHCB's shared buffer. Note, things like Page State Change\n(PSC) requests _rely_ on this behavior, as the guest can't provide a length\nwhen making the request, i.e. the size of the guest payload is bounded by\nthe size of the shared buffer.\n\nFailure to force usage of the GHCB, and a slew of other flaws, lets a\nmalicious SNP guest corrupt host kernel heap memory, and leak host heap\nlayout information.\n\nsetup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2),\nwhere exit_info_2 is guest-controlled. With exit_info_2=24, this yields\na 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer\nholds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only\nentries[0] and entries[1] are in-bounds.\n\nsnp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253)\nbut NOT against the actual buffer size:\n\n idx_end = hdr->end_entry;\n\n if (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer\n snp_complete_psc(svm, ...);\n return 1;\n }\n\n for (idx = idx_start; idx <= idx_end; idx++) {\n entry_start = entries[idx]; // OOB when idx >= 2\n\nThe guest sets end_entry=10+, causing the host to iterate entries[2+]\nwhich are OOB into adjacent slab objects. For each OOB entry:\n\n - The host reads 8 bytes (OOB READ / info leak oracle)\n - If the data passes PSC validation, __snp_complete_one_psc() writes\n cur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806)\n - If validation fails, the error response reveals whether adjacent\n memory is zero vs non-zero (information disclosure to guest)\n\nThe guest controls allocation size (exit_info_2), entry range\n(cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly\nhit different slab positions.\n\nBy exploiting the variety of bugs, a malicious SEV-SNP guest can:\n - OOB read adjacent kmalloc-cg-32 objects (heap layout disclosure)\n - OOB write cur_page bits into adjacent objects (heap corruption)\n - Trigger use-after-free conditions across VMGEXITs\n\nE.g. with KASAN enabled, a single insmod of the PoC guest module\nproduces 73 KASAN reports:\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x126/0x890\n Read of size 8 at addr ffff888219ffb5e0 by task qemu-system-x86/2199\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x468/0x890\n Write of size 8 at addr ffff888351566648 by task qemu-system-x86/2199\n\n The buggy address belongs to the object at ffff888XXXXXXXXX\n which belongs to the cache kmalloc-cg-32 of size 32\n The buggy address is located N bytes to the right of\n allocated 32-byte region [ffff888XXXXXXXXX, ffff888XXXXXXXXX)\n\n Breakdown:\n 62 slab-out-of-bounds (reads + writes past allocation)\n 7 slab-use-after-free\n 4 use-after-free\n\nAll credit to Stan for the wonderful description and reproducer!\n\n[sean: write changelog]"}], "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 vulnerable path is reached by running a SEV-SNP vCPU through KVM and issuing a guest-controlled VMGEXIT PSC request, not by remote packets or adjacent/physical access.\nAC:L - The guest directly controls the scratch pointer/length and PSC entry bounds, and can repeatedly issue malformed VMGEXITs without needing external races or rare timing conditions.\nPR:L - Exploitation requires the ability to run or control a SEV-SNP guest/KVM vCPU, which is a low-privilege local or tenant capability rather than real host root in the init namespace.\nUI:N - Once the attacker controls the malicious guest or VM process, no additional victim action is required to trigger the VMGEXIT handling path.\nS:C - The bug lets a malicious guest corrupt and disclose host kernel heap memory, crossing the guest-to-host virtualization security boundary.\nC:H - The OOB reads and error oracle leak adjacent host heap contents/layout, and the associated memory corruption/UAF behavior is sufficient to treat confidentiality impact as high.\nI:H - The vulnerable path performs OOB writes into adjacent host slab objects and can trigger UAF conditions, making host kernel memory corruption and potential control-flow compromise defensible.\nA:H - The bug produces host kernel slab OOB writes/reads and UAF reports and can crash or destabilize the host kernel, giving high availability impact."}]}], "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": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "lessThan": "bf9ba093fbb83c0c9a3dedd50efec29424eca2fc", "status": "affected", "versionType": "git"}, {"version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "lessThan": "c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae", "status": "affected", "versionType": "git"}, {"version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "lessThan": "b328ede59ac34e7998e1eee5e5f0cc26c2a91846", "status": "affected", "versionType": "git"}, {"version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "lessThan": "db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7", "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": "6.10", "status": "affected"}, {"version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.12", "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": "6.10", "versionEndExcluding": "6.12.93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.18.35"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.0.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bf9ba093fbb83c0c9a3dedd50efec29424eca2fc"}, {"url": "https://git.kernel.org/stable/c/c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae"}, {"url": "https://git.kernel.org/stable/c/b328ede59ac34e7998e1eee5e5f0cc26c2a91846"}, {"url": "https://git.kernel.org/stable/c/db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7"}], "title": "KVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-53360", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:29:05.458760Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds Write"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:07:44.426Z"}}]}}

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Note, things like Page State Change\n(PSC) requests _rely_ on this behavior, as the guest can't provide a length\nwhen making the request, i.e. the size of the guest payload is bounded by\nthe size of the shared buffer.\n\nFailure to force usage of the GHCB, and a slew of other flaws, lets a\nmalicious SNP guest corrupt host kernel heap memory, and leak host heap\nlayout information.\n\nsetup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2),\nwhere exit_info_2 is guest-controlled. With exit_info_2=24, this yields\na 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer\nholds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only\nentries[0] and entries[1] are in-bounds.\n\nsnp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253)\nbut NOT against the actual buffer size:\n\n idx_end = hdr->end_entry;\n\n if (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer\n snp_complete_psc(svm, ...);\n return 1;\n }\n\n for (idx = idx_start; idx <= idx_end; idx++) {\n entry_start = entries[idx]; // OOB when idx >= 2\n\nThe guest sets end_entry=10+, causing the host to iterate entries[2+]\nwhich are OOB into adjacent slab objects. For each OOB entry:\n\n - The host reads 8 bytes (OOB READ / info leak oracle)\n - If the data passes PSC validation, __snp_complete_one_psc() writes\n cur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806)\n - If validation fails, the error response reveals whether adjacent\n memory is zero vs non-zero (information disclosure to guest)\n\nThe guest controls allocation size (exit_info_2), entry range\n(cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly\nhit different slab positions.\n\nBy exploiting the variety of bugs, a malicious SEV-SNP guest can:\n - OOB read adjacent kmalloc-cg-32 objects (heap layout disclosure)\n - OOB write cur_page bits into adjacent objects (heap corruption)\n - Trigger use-after-free conditions across VMGEXITs\n\nE.g. with KASAN enabled, a single insmod of the PoC guest module\nproduces 73 KASAN reports:\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x126/0x890\n Read of size 8 at addr ffff888219ffb5e0 by task qemu-system-x86/2199\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x468/0x890\n Write of size 8 at addr ffff888351566648 by task qemu-system-x86/2199\n\n The buggy address belongs to the object at ffff888XXXXXXXXX\n which belongs to the cache kmalloc-cg-32 of size 32\n The buggy address is located N bytes to the right of\n allocated 32-byte region [ffff888XXXXXXXXX, ffff888XXXXXXXXX)\n\n Breakdown:\n 62 slab-out-of-bounds (reads + writes past allocation)\n 7 slab-use-after-free\n 4 use-after-free\n\nAll credit to Stan for the wonderful description and reproducer!\n\n[sean: write changelog]"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.93", "versionStartIncluding": "6.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.35", "versionStartIncluding": "6.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0.12", "versionStartIncluding": "6.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1", "versionStartIncluding": "6.10"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:35:09.892Z"}}}, "cveMetadata": {"cveId": "CVE-2026-53360", "state": "PUBLISHED", "dateUpdated": "2026-10-19T20:07:44.426Z", "dateReserved": "2026-06-09T07:44:35.400Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-07-04T11:53:58.657Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"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": "bf9ba093fbb83c0c9a3dedd50efec29424eca2fc", "status": "affected", "version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "versionType": "git"}, {"lessThan": "c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae", "status": "affected", "version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "versionType": "git"}, {"lessThan": "b328ede59ac34e7998e1eee5e5f0cc26c2a91846", "status": "affected", "version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "versionType": "git"}, {"lessThan": "db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7", "status": "affected", "version": "4af663c2f64a8d252e690c60cf8b8abf22dc2951", "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": "6.10"}, {"lessThan": "6.10", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.93", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.35", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.12", "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": "BF682514-ED2D-408F-97D2-89BF524B87D8", "versionEndExcluding": "6.12.93", "versionStartIncluding": "6.10", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0FCCB23A-7629-4386-93B6-B119237C4382", "versionEndExcluding": "6.18.35", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9161A938-0FA8-44BC-95FE-C5A271601AB3", "versionEndExcluding": "7.0.12", "versionStartIncluding": "6.19", "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}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*", "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use\n\nAs per the GHCB spec, when using GHCB v2+ require the software scratch area\nto reside in the GHCB's shared buffer. Note, things like Page State Change\n(PSC) requests _rely_ on this behavior, as the guest can't provide a length\nwhen making the request, i.e. the size of the guest payload is bounded by\nthe size of the shared buffer.\n\nFailure to force usage of the GHCB, and a slew of other flaws, lets a\nmalicious SNP guest corrupt host kernel heap memory, and leak host heap\nlayout information.\n\nsetup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2),\nwhere exit_info_2 is guest-controlled. With exit_info_2=24, this yields\na 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer\nholds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only\nentries[0] and entries[1] are in-bounds.\n\nsnp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253)\nbut NOT against the actual buffer size:\n\n idx_end = hdr->end_entry;\n\n if (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer\n snp_complete_psc(svm, ...);\n return 1;\n }\n\n for (idx = idx_start; idx <= idx_end; idx++) {\n entry_start = entries[idx]; // OOB when idx >= 2\n\nThe guest sets end_entry=10+, causing the host to iterate entries[2+]\nwhich are OOB into adjacent slab objects. For each OOB entry:\n\n - The host reads 8 bytes (OOB READ / info leak oracle)\n - If the data passes PSC validation, __snp_complete_one_psc() writes\n cur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806)\n - If validation fails, the error response reveals whether adjacent\n memory is zero vs non-zero (information disclosure to guest)\n\nThe guest controls allocation size (exit_info_2), entry range\n(cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly\nhit different slab positions.\n\nBy exploiting the variety of bugs, a malicious SEV-SNP guest can:\n - OOB read adjacent kmalloc-cg-32 objects (heap layout disclosure)\n - OOB write cur_page bits into adjacent objects (heap corruption)\n - Trigger use-after-free conditions across VMGEXITs\n\nE.g. with KASAN enabled, a single insmod of the PoC guest module\nproduces 73 KASAN reports:\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x126/0x890\n Read of size 8 at addr ffff888219ffb5e0 by task qemu-system-x86/2199\n\n BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x468/0x890\n Write of size 8 at addr ffff888351566648 by task qemu-system-x86/2199\n\n The buggy address belongs to the object at ffff888XXXXXXXXX\n which belongs to the cache kmalloc-cg-32 of size 32\n The buggy address is located N bytes to the right of\n allocated 32-byte region [ffff888XXXXXXXXX, ffff888XXXXXXXXX)\n\n Breakdown:\n 62 slab-out-of-bounds (reads + writes past allocation)\n 7 slab-use-after-free\n 4 use-after-free\n\nAll credit to Stan for the wonderful description and reproducer!\n\n[sean: write changelog]"}], "id": "CVE-2026-53360", "lastModified": "2026-10-19T20:19:16.147", "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-53360", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:29:05.458760Z", "version": "2.0.3"}}]}, "published": "2026-07-04T12:17:01.880", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b328ede59ac34e7998e1eee5e5f0cc26c2a91846"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/bf9ba093fbb83c0c9a3dedd50efec29424eca2fc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-787"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: KVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use", "id": "2497032", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2497032"}, "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-787", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nKVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use\nAs per the GHCB spec, when using GHCB v2+ require the software scratch area\nto reside in the GHCB's shared buffer. Note, things like Page State Change\n(PSC) requests _rely_ on this behavior, as the guest can't provide a length\nwhen making the request, i.e. the size of the guest payload is bounded by\nthe size of the shared buffer.\nFailure to force usage of the GHCB, and a slew of other flaws, lets a\nmalicious SNP guest corrupt host kernel heap memory, and leak host heap\nlayout information.\nsetup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2),\nwhere exit_info_2 is guest-controlled. With exit_info_2=24, this yields\na 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer\nholds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only\nentries[0] and entries[1] are in-bounds.\nsnp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253)\nbut NOT against the actual buffer size:\nidx_end = hdr->end_entry;\nif (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer\nsnp_complete_psc(svm, ...);\nreturn 1;\n}\nfor (idx = idx_start; idx <= idx_end; idx++) {\nentry_start = entries[idx]; // OOB when idx >= 2\nThe guest sets end_entry=10+, causing the host to iterate entries[2+]\nwhich are OOB into adjacent slab objects. For each OOB entry:\n- The host reads 8 bytes (OOB READ / info leak oracle)\n- If the data passes PSC validation, __snp_complete_one_psc() writes\ncur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806)\n- If validation fails, the error response reveals whether adjacent\nmemory is zero vs non-zero (information disclosure to guest)\nThe guest controls allocation size (exit_info_2), entry range\n(cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly\nhit different slab positions.\nBy exploiting the variety of bugs, a malicious SEV-SNP guest can:\n- OOB read adjacent kmalloc-cg-32 objects (heap layout disclosure)\n- OOB write cur_page bits into adjacent objects (heap corruption)\n- Trigger use-after-free conditions across VMGEXITs\nE.g. with KASAN enabled, a single insmod of the PoC guest module\nproduces 73 KASAN reports:\nBUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x126/0x890\nRead of size 8 at addr ffff888219ffb5e0 by task qemu-system-x86/2199\nBUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x468/0x890\nWrite of size 8 at addr ffff888351566648 by task qemu-system-x86/2199\nThe buggy address belongs to the object at ffff888XXXXXXXXX\nwhich belongs to the cache kmalloc-cg-32 of size 32\nThe buggy address is located N bytes to the right of\nallocated 32-byte region [ffff888XXXXXXXXX, ffff888XXXXXXXXX)\nBreakdown:\n62 slab-out-of-bounds (reads + writes past allocation)\n7 slab-use-after-free\n4 use-after-free\nAll credit to Stan for the wonderful description and reproducer!\n[sean: write changelog]", "A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem, specifically within the SEV (Secure Encrypted Virtualization) feature. A malicious guest operating system utilizing SEV-SNP (Secure Nested Paging) can exploit an out-of-bounds write vulnerability due to improper validation of guest-controlled input during Guest-Host Communication Block (GHCB) operations. This allows the guest to read and write beyond allocated memory regions, leading to host kernel heap memory corruption and disclosure of sensitive heap layout information. This could enable a malicious guest to escalate privileges on the host system."], "name": "CVE-2026-53360", "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": "2026-07-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-53360\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53360\nhttps://lore.kernel.org/linux-cve-announce/2026070413-CVE-2026-53360-3284@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[4af663c2f64a8d252e690c60cf8b8abf22dc2951,bf9ba093fbb83c0c9a3dedd50efec29424eca2fc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[4af663c2f64a8d252e690c60cf8b8abf22dc2951,c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[4af663c2f64a8d252e690c60cf8b8abf22dc2951,b328ede59ac34e7998e1eee5e5f0cc26c2a91846)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[4af663c2f64a8d252e690c60cf8b8abf22dc2951,db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7)"}}], "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": "generic", "value": "6.10"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.10)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.93,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.35,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0.12,7.0.*]"}}, {"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": "2026-07-04T13:30:16.245506+00:00", "updated": "2026-08-13T12:30:10.770489+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}