{"api_version":"1","generated_at":"2026-09-14T08:03:53+00:00","cve":"CVE-2026-80929","urls":{"html":"https://cve.report/CVE-2026-80929","api":"https://cve.report/api/cve/CVE-2026-80929.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80929","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80929"},"summary":{"title":"sysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]\n\ncad_pid is global, and kill_cad_pid() is only used in the root namespace.\n\nHowever, due to pid_table_root_permissions(), a non-root user can unshare\npid/user namespaces and modify it from the child namespace. This makes no\nsense and is simply wrong.\n\nMove it to kern_reboot_table[] where it logically belongs; this ensures\nthat only GLOBAL_ROOT_UID can read/modify this sysctl.\n\nNote that this patch doesn't preserve \"#ifdef CONFIG_PROC_SYSCTL\" around\nthe \"cad_pid\"; CONFIG_PROC_SYSCTL selects CONFIG_SYSCTL, so it is always\nset when kern_reboot_table[] is compiled.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:18:56","updated_at":"2026-09-13 07:17:00"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/e8527de7fea191fda704792a56081f9009aeec37","name":"https://git.kernel.org/stable/c/e8527de7fea191fda704792a56081f9009aeec37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd","name":"https://git.kernel.org/stable/c/a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7170ca01623b399c97f2ae9d3e228badc1f25ea3","name":"https://git.kernel.org/stable/c/7170ca01623b399c97f2ae9d3e228badc1f25ea3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80929","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80929","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e054bcbe7e7af2baad3752f1a4916a7fffc0457e e8527de7fea191fda704792a56081f9009aeec37 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e054bcbe7e7af2baad3752f1a4916a7fffc0457e a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e054bcbe7e7af2baad3752f1a4916a7fffc0457e 7170ca01623b399c97f2ae9d3e228badc1f25ea3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.17","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80929","cve":"CVE-2026-80929","epss":"0.001610000","percentile":"0.056700000","score_date":"2026-09-13","updated_at":"2026-09-14 00:18:01"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/pid.c","kernel/reboot.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"e8527de7fea191fda704792a56081f9009aeec37","status":"affected","version":"e054bcbe7e7af2baad3752f1a4916a7fffc0457e","versionType":"git"},{"lessThan":"a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd","status":"affected","version":"e054bcbe7e7af2baad3752f1a4916a7fffc0457e","versionType":"git"},{"lessThan":"7170ca01623b399c97f2ae9d3e228badc1f25ea3","status":"affected","version":"e054bcbe7e7af2baad3752f1a4916a7fffc0457e","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/pid.c","kernel/reboot.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.17"},{"lessThan":"6.17","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.17","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]\n\ncad_pid is global, and kill_cad_pid() is only used in the root namespace.\n\nHowever, due to pid_table_root_permissions(), a non-root user can unshare\npid/user namespaces and modify it from the child namespace. This makes no\nsense and is simply wrong.\n\nMove it to kern_reboot_table[] where it logically belongs; this ensures\nthat only GLOBAL_ROOT_UID can read/modify this sysctl.\n\nNote that this patch doesn't preserve \"#ifdef CONFIG_PROC_SYSCTL\" around\nthe \"cad_pid\"; CONFIG_PROC_SYSCTL selects CONFIG_SYSCTL, so it is always\nset when kern_reboot_table[] is compiled."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - Unprivileged local processes reach proc_do_cad_pid() by opening and writing /proc/sys/kernel/cad_pid after creating user and PID namespaces; this is a procfs sysctl syscall path, not a network, adjacent-wireless, or physical-device handler.\nAC:L - The attacker fully controls namespace creation and concurrent sysctl reads/writes of the shared global cad_pid pointer, so the proc_do_cad_pid() use-after-free race does not depend on victim state, rare configs, or other conditions outside attacker influence.\nPR:L - pid_table_root_permissions() treats CAP_SYS_ADMIN or uid 0 in the PID namespace's user namespace as owner of the 0600 cad_pid sysctl, which an unprivileged user obtains by unsharing user and PID namespaces rather than needing init-namespace root.\nUI:N - The attacker triggers the flaw entirely through their own unshare, proc mount, and read/write of kernel.cad_pid; no other user must press Ctrl-Alt-Del, mount a filesystem, or take any action.\nS:U - Successful exploitation corrupts host kernel memory and hijacks the global cad_pid used by kill_cad_pid(); this remains inside the kernel's security authority and is not a VM, IOMMU, or DMA boundary bypass.\nC:H - Racing a cad_pid sysctl write (put_pid of the last reference) against a sysctl read use-after-frees struct pid in pid_vnr()/pid_nr_ns(), which per kernel CVSS guidance provides an arbitrary kernel-read primitive via slab reuse.\nI:H - The same use-after-free of struct pid is exploitable for heap spraying and control-flow hijack of kernel PID/signal paths, and the write also replaces host-global cad_pid so privileged kernel SIGINT/SIGPWR are redirected away from init.\nA:H - The use-after-free produces a kernel oops or panic on the pid_nr_ns() dereference of freed memory, as shown by the KASAN report; replacing cad_pid also persistently breaks host Ctrl-Alt-Del and power-button delivery to init."}]}],"providerMetadata":{"dateUpdated":"2026-09-13T06:28:10.105Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/e8527de7fea191fda704792a56081f9009aeec37"},{"url":"https://git.kernel.org/stable/c/a09bc4eaa67e1a72df3b6d0beb3afeef1e1fdfcd"},{"url":"https://git.kernel.org/stable/c/7170ca01623b399c97f2ae9d3e228badc1f25ea3"}],"title":"sysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80929","datePublished":"2026-09-11T19:42:04.778Z","dateReserved":"2026-08-26T14:34:25.802Z","dateUpdated":"2026-09-13T06:28:10.105Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:18:56","lastModifiedDate":"2026-09-13 07:17:00","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80929","Ordinal":"1","Title":"sysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot","CVE":"CVE-2026-80929","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80929","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nsysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot_table[]\n\ncad_pid is global, and kill_cad_pid() is only used in the root namespace.\n\nHowever, due to pid_table_root_permissions(), a non-root user can unshare\npid/user namespaces and modify it from the child namespace. This makes no\nsense and is simply wrong.\n\nMove it to kern_reboot_table[] where it logically belongs; this ensures\nthat only GLOBAL_ROOT_UID can read/modify this sysctl.\n\nNote that this patch doesn't preserve \"#ifdef CONFIG_PROC_SYSCTL\" around\nthe \"cad_pid\"; CONFIG_PROC_SYSCTL selects CONFIG_SYSCTL, so it is always\nset when kern_reboot_table[] is compiled.","Type":"Description","Title":"sysctl: move the \"cad_pid\" entry from pid_table[] to kern_reboot"}]}}}