{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-63794 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-63794 is a high-severity memory corruption vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-63794 and fix it if it is affected.\n\nWhat it is: CVE-2026-63794 is a high-severity memory corruption vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-63794 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-63794/ (Markdown: https://insights.sbomify.com/CVE-2026-63794/index.md)","id":"CVE-2026-63794","markdown":"https://insights.sbomify.com/CVE-2026-63794/index.md","name":"CVE-2026-63794","record":{"aliases":["BELL-CVE-2026-63794","DEBIAN-CVE-2026-63794","GHSA-8vm9-66j5-xm27","ROOT-OS-DEBIAN-11-CVE-2026-63794","ROOT-OS-UBUNTU-2204-CVE-2026-63794","UBUNTU-CVE-2026-63794"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel KVM","requires_auth":"low_privilege","summary":"A buffer overflow in the Linux kernel's KVM SVM module allows local attackers to corrupt memory and potentially execute code or escalate privileges.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path\n\nIn sev_dbg_crypt(), the per-iteration transfer length is bounded by\nthe source page offset (PAGE_SIZE - s_off) but not by the destination\npage offset (PAGE_SIZE - d_off).  When d_off \u003e s_off, the encrypt\npath (__sev_dbg_encrypt_user) performs a read-modify-write using a\nsingle-page intermediate buffer (dst_tpage):\n\n  1. __sev_dbg_decrypt() expands the size to round_up(len + (d_off \u0026 15), 16)\n     before issuing the PSP command.  If len + (d_off \u0026 15) \u003e PAGE_SIZE,\n     the PSP writes beyond the end of the 4096-byte dst_tpage allocation.\n\n  2. The subsequent memcpy()/copy_from_user() into\n     page_address(dst_tpage) + (d_off \u0026 15) of 'len' bytes overflows\n     by up to 15 bytes under the same condition.\n\nTrigger example: s_off = 0, d_off = 1, debug.len = PAGE_SIZE -\nthe PSP is instructed to write round_up(4097, 16) = 4112 bytes to\na 4096-byte buffer.\n\nFix by also bounding len by (PAGE_SIZE - d_off), the same check that\nsev_send_update_data() already performs for its single-page guest\nregion.\n\n ==================================================================\n BUG: KASAN: slab-use-after-free in sev_dbg_crypt+0x993/0xd10 [kvm_amd]\n Write of size 4095 at addr ff110062293bb009 by task sev_dbg_test/228214\n\n CPU: 96 UID: 0 PID: 228214 Comm: sev_dbg_test Tainted: G     U  W           7.0.0-smp--5ce9b0c48211-dbg #156 PREEMPTLAZY\n Tainted: [U]=USER, [W]=WARN\n Hardware name: Google Astoria/astoria, BIOS 0.20250817.1-0 08/25/2025\n Call Trace:\n  \u003cTASK\u003e\n  dump_stack_lvl+0x54/0x70\n  print_report+0xbc/0x260\n  kasan_report+0xa2/0xd0\n  kasan_check_range+0x25f/0x2c0\n  __asan_memcpy+0x40/0x70\n  sev_dbg_crypt+0x993/0xd10 [kvm_amd]\n  sev_mem_enc_ioctl+0x33c/0x450 [kvm_amd]\n  kvm_vm_ioctl+0x65d/0x6d0 [kvm]\n  __se_sys_ioctl+0xb2/0x100\n  do_syscall_64+0xe8/0x870\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  \u003c/TASK\u003e\n\n The buggy address belongs to the physical page:\n page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7fe72b6a0 pfn:0x62293bb\n memcg:ff11000112827d82\n flags: 0x1400000000000000(node=1|zone=1)\n raw: 1400000000000000 0000000000000000 dead000000000122 0000000000000000\n raw: 00000007fe72b6a0 0000000000000000 00000001ffffffff ff11000112827d82\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n  ff110062293bbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n  ff110062293bbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n \u003eff110062293bc000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n                    ^\n  ff110062293bc080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n  ff110062293bc100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n ==================================================================\n Disabling lock debugging due to kernel taint\n\n[sean: add sample KASAN splat, Fixes, and stable@]","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path","id":"CVE-2026-63794","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"9p: avoid putting oldfid in p9_client_walk() error path","id":"CVE-2026-63795"},"packages":[],"prev":{"headline":"ntfs: serialize volume label accesses","id":"CVE-2026-63793"},"products":["Linux"],"published":"2026-07-19","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-17","vendors":["Linux"]},"summary":"A buffer overflow in the Linux kernel's KVM SVM module allows local attackers to corrupt memory and potentially execute code or escalate privileges.","url":"https://insights.sbomify.com/CVE-2026-63794/"}