{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21872 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21872 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Mar 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-2025-21872 and fix it if it is affected.\n\nWhat it is: CVE-2025-21872 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Mar 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-2025-21872 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-2025-21872/ (Markdown: https://insights.sbomify.com/CVE-2025-21872/index.md)","id":"CVE-2025-21872","markdown":"https://insights.sbomify.com/CVE-2025-21872/index.md","name":"CVE-2025-21872","record":{"aliases":["AZL-69491","BELL-CVE-2025-21872","DEBIAN-CVE-2025-21872","GHSA-9pcq-fqff-43qc","ROOT-OS-DEBIAN-12-CVE-2025-21872","ROOT-OS-UBUNTU-2204-CVE-2025-21872","ROOT-OS-UBUNTU-2404-CVE-2025-21872","UBUNTU-CVE-2025-21872"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A flaw in the Linux kernel EFI MOKvar table initialization causes a kernel warning and potential failure when mapping large tables, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nefi: Don't map the entire mokvar table to determine its size\n\nCurrently, when validating the mokvar table, we (re)map the entire table\non each iteration of the loop, adding space as we discover new entries.\nIf the table grows over a certain size, this fails due to limitations of\nearly_memmap(), and we get a failure and traceback:\n\n  ------------[ cut here ]------------\n  WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220\n  ...\n  Call Trace:\n   \u003cTASK\u003e\n   ? __early_ioremap+0xef/0x220\n   ? __warn.cold+0x93/0xfa\n   ? __early_ioremap+0xef/0x220\n   ? report_bug+0xff/0x140\n   ? early_fixup_exception+0x5d/0xb0\n   ? early_idt_handler_common+0x2f/0x3a\n   ? __early_ioremap+0xef/0x220\n   ? efi_mokvar_table_init+0xce/0x1d0\n   ? setup_arch+0x864/0xc10\n   ? start_kernel+0x6b/0xa10\n   ? x86_64_start_reservations+0x24/0x30\n   ? x86_64_start_kernel+0xed/0xf0\n   ? common_startup_64+0x13e/0x141\n   \u003c/TASK\u003e\n  ---[ end trace 0000000000000000 ]---\n  mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187.\n\nMapping the entire structure isn't actually necessary, as we don't ever\nneed more than one entry header mapped at once.\n\nChanges efi_mokvar_table_init() to only map each entry header, not the\nentire table, when determining the table size.  Since we're not mapping\nany data past the variable name, it also changes the code to enforce\nthat each variable name is NUL terminated, rather than attempting to\nverify it in place.","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":"efi: Don't map the entire mokvar table to determine its size","id":"CVE-2025-21872","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2025"},"n_packages":0,"n_references":5,"next":{"headline":"scsi: ufs: core: bsg: Fix crash when arpmb command fails","id":"CVE-2025-21873"},"packages":[],"prev":{"headline":"tee: optee: Fix supplicant wait loop","id":"CVE-2025-21871"},"products":["Linux"],"published":"2025-03-27","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A flaw in the Linux kernel EFI MOKvar table initialization causes a kernel warning and potential failure when mapping large tables, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2025-21872/"}