{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21991 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21991 is a high-severity memory corruption vulnerability in Linux kernel, published on 2 Apr 2025. 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-2025-21991 and fix it if it is affected.\n\nWhat it is: CVE-2025-21991 is a high-severity memory corruption vulnerability in Linux kernel, published on 2 Apr 2025. 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-2025-21991 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-2025-21991/ (Markdown: https://insights.sbomify.com/CVE-2025-21991/index.md)","id":"CVE-2025-21991","markdown":"https://insights.sbomify.com/CVE-2025-21991/index.md","name":"CVE-2025-21991","record":{"aliases":["ALSA-2025:10837","AZL-59785","AZL-59843","BELL-CVE-2025-21991","DEBIAN-CVE-2025-21991","GHSA-vp9x-33x6-jvvm","RHSA-2025:10837","RLSA-2025:10837","ROOT-OS-UBUNTU-2404-CVE-2025-21991","UBUNTU-CVE-2025-21991"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"Out-of-bounds memory access in AMD microcode loading on CPU-less NUMA nodes can cause kernel crashes or memory corruption during privileged updates.","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":"cisa-adp","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-129","name":"Improper Validation of Array Index"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes\n\nCurrently, load_microcode_amd() iterates over all NUMA nodes, retrieves their\nCPU masks and unconditionally accesses per-CPU data for the first CPU of each\nmask.\n\nAccording to Documentation/admin-guide/mm/numaperf.rst:\n\n  \"Some memory may share the same node as a CPU, and others are provided as\n  memory only nodes.\"\n\nTherefore, some node CPU masks may be empty and wouldn't have a \"first CPU\".\n\nOn a machine with far memory (and therefore CPU-less NUMA nodes):\n- cpumask_of_node(nid) is 0\n- cpumask_first(0) is CONFIG_NR_CPUS\n- cpu_data(CONFIG_NR_CPUS) accesses the cpu_info per-CPU array at an\n  index that is 1 out of bounds\n\nThis does not have any security implications since flashing microcode is\na privileged operation but I believe this has reliability implications by\npotentially corrupting memory while flashing a microcode update.\n\nWhen booting with CONFIG_UBSAN_BOUNDS=y on an AMD machine that flashes\na microcode update. I get the following splat:\n\n  UBSAN: array-index-out-of-bounds in arch/x86/kernel/cpu/microcode/amd.c:X:Y\n  index 512 is out of range for type 'unsigned long[512]'\n  [...]\n  Call Trace:\n   dump_stack\n   __ubsan_handle_out_of_bounds\n   load_microcode_amd\n   request_microcode_amd\n   reload_store\n   kernfs_fop_write_iter\n   vfs_write\n   ksys_write\n   do_syscall_64\n   entry_SYSCALL_64_after_hwframe\n\nChange the loop to go over only NUMA nodes which have CPUs before determining\nwhether the first CPU on the respective node needs microcode update.\n\n  [ bp: Massage commit message, fix typo. ]","ecosystems":["AlmaLinux:9","Red Hat:enterprise_linux:9::appstream","Red Hat:enterprise_linux:9::baseos","Red Hat:enterprise_linux:9::crb","Red Hat:enterprise_linux:9::nfv","Red Hat:enterprise_linux:9::realtime","Rocky Linux:9"],"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":"x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes","id":"CVE-2025-21991","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2025"},"n_packages":237,"n_references":8,"next":{"headline":"HID: ignore non-functional sensor in HP 5MP Camera","id":"CVE-2025-21992"},"packages":[{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel","purl":"pkg:rpm/almalinux/kernel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k","purl":"pkg:rpm/almalinux/kernel-64k","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-core","purl":"pkg:rpm/almalinux/kernel-64k-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug","purl":"pkg:rpm/almalinux/kernel-64k-debug","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-core","purl":"pkg:rpm/almalinux/kernel-64k-debug-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-devel","purl":"pkg:rpm/almalinux/kernel-64k-debug-devel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-devel-matched","purl":"pkg:rpm/almalinux/kernel-64k-debug-devel-matched","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-modules","purl":"pkg:rpm/almalinux/kernel-64k-debug-modules","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-modules-core","purl":"pkg:rpm/almalinux/kernel-64k-debug-modules-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-debug-modules-extra","purl":"pkg:rpm/almalinux/kernel-64k-debug-modules-extra","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-devel","purl":"pkg:rpm/almalinux/kernel-64k-devel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-devel-matched","purl":"pkg:rpm/almalinux/kernel-64k-devel-matched","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-modules","purl":"pkg:rpm/almalinux/kernel-64k-modules","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-modules-core","purl":"pkg:rpm/almalinux/kernel-64k-modules-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-64k-modules-extra","purl":"pkg:rpm/almalinux/kernel-64k-modules-extra","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-abi-stablelists","purl":"pkg:rpm/almalinux/kernel-abi-stablelists","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-core","purl":"pkg:rpm/almalinux/kernel-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-cross-headers","purl":"pkg:rpm/almalinux/kernel-cross-headers","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug","purl":"pkg:rpm/almalinux/kernel-debug","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-core","purl":"pkg:rpm/almalinux/kernel-debug-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-devel","purl":"pkg:rpm/almalinux/kernel-debug-devel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-devel-matched","purl":"pkg:rpm/almalinux/kernel-debug-devel-matched","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-modules","purl":"pkg:rpm/almalinux/kernel-debug-modules","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-modules-core","purl":"pkg:rpm/almalinux/kernel-debug-modules-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-modules-extra","purl":"pkg:rpm/almalinux/kernel-debug-modules-extra","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-uki-virt","purl":"pkg:rpm/almalinux/kernel-debug-uki-virt","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-devel","purl":"pkg:rpm/almalinux/kernel-devel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-devel-matched","purl":"pkg:rpm/almalinux/kernel-devel-matched","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-doc","purl":"pkg:rpm/almalinux/kernel-doc","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-headers","purl":"pkg:rpm/almalinux/kernel-headers","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-modules","purl":"pkg:rpm/almalinux/kernel-modules","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-modules-core","purl":"pkg:rpm/almalinux/kernel-modules-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-modules-extra","purl":"pkg:rpm/almalinux/kernel-modules-extra","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt","purl":"pkg:rpm/almalinux/kernel-rt","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k","purl":"pkg:rpm/almalinux/kernel-rt-64k","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k-core","purl":"pkg:rpm/almalinux/kernel-rt-64k-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k-debug","purl":"pkg:rpm/almalinux/kernel-rt-64k-debug","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k-debug-core","purl":"pkg:rpm/almalinux/kernel-rt-64k-debug-core","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k-debug-devel","purl":"pkg:rpm/almalinux/kernel-rt-64k-debug-devel","source":"ALSA-2025:10837"},{"ecosystem":"AlmaLinux:9","fixed":["5.14.0-570.26.1.el9_6"],"introduced":["0"],"last_affected":[],"package":"kernel-rt-64k-debug-modules","purl":"pkg:rpm/almalinux/kernel-rt-64k-debug-modules","source":"ALSA-2025:10837"}],"prev":{"headline":"drm/amdgpu: NULL-check BO's backing store when determining GFX12 PTE flags","id":"CVE-2025-21990"},"products":["Linux"],"published":"2025-04-02","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":"MIT","name":"AlmaLinux","prefix":"ALSA"},{"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":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-05-23","vendors":["Linux"]},"summary":"Out-of-bounds memory access in AMD microcode loading on CPU-less NUMA nodes can cause kernel crashes or memory corruption during privileged updates.","url":"https://insights.sbomify.com/CVE-2025-21991/"}