{"id":"CVE-2025-38352","published":"2025-07-22T08:15:23Z","modified":"2026-09-08T18:17:32Z","title":"Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability","vendor":"Linux","product":"Kernel","tier":"core","eol":null,"description":{"text":"In the Linux kernel, the following vulnerability has been resolved:\n\nposix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()\n\nIf an exiting non-autoreaping task has already passed exit_notify() and\ncalls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent\nor debugger right after unlock_task_sighand().\n\nIf a concurrent posix_cpu_timer_del() runs at that moment, it won't be\nable to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or\nlock_task_sighand() will fail.\n\nAdd the tsk->exit_state check into run_posix_cpu_timers() to fix this.\n\nThis fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because\nexit_task_work() is called before exit_notify(). But the check still\nmakes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail\nanyway in this case.","provenance":"source","from":"NVD"},"summary":{"text":"The Linux kernel's POSIX CPU timer code contains a time-of-check to time-of-use race condition between handle_posix_cpu_timers() and posix_cpu_timer_del(), where an exiting non-autoreaping task can be reaped by its parent or a debugger while a concurrent timer deletion is in progress. An attacker able to run code locally with low privileges and no user interaction could exploit this race to affect confidentiality, integrity and availability.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:03Z"},"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.01357,"percentile":0.71593,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2025-09-04","dueDate":"2025-09-25","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"This vulnerability affects a common open-source component, third-party library, or a protocol used by different products. Please check with specific vendors for information on patching status. For more information, please see: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff ; https://source.android.com/docs/security/bulletin/2025-09-01 ; https://nvd.nist.gov/vuln/detail/CVE-2025-38352","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-09-01","exploitedFirstSeen":"2025-09-01","ransomware":false,"evidence":[{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2025-09-01"},{"url":"https://source.android.com/docs/security/bulletin/2025-09-01","date":"2025-09-02"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-09-04"},{"url":"https://www.rapid7.com/cdn/assets/bltbd2f1cd70f9e3e7f/691360b9c91291146f1a5308/threat-landscape-report-q3-2025.pdf","date":"2025-11-12"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"},{"url":"https://cloud.google.com/blog/topics/threat-intelligence/2025-zero-day-review","date":"2026-03-05"},{"url":"https://www.redhat.com/en/resources/product-security-risk-report-2025","date":"2026-04-10"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-367","name":"Time-of-check Time-of-use (TOCTOU) Race Condition"}],"references":[{"url":"https://git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca","tags":["Patch"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","tags":["Mailing List","Third Party Advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","tags":["Mailing List","Third Party Advisory"]},{"url":"https://github.com/farazsth98/chronomaly","tags":["Exploit"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352","tags":["US Government Resource"]}],"techniques":[],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-22297","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-22297","exploited":true,"exploitedSince":"2025-09-04","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":5,"skipped":1,"earliest":"2025-12-21","earliestUrl":"https://github.com/farazsth98/poc-CVE-2025-38352","repos":[{"name":"farazsth98/chronomaly","url":"https://github.com/farazsth98/chronomaly","stars":312,"created":"2026-01-03"},{"name":"farazsth98/poc-CVE-2025-38352","url":"https://github.com/farazsth98/poc-CVE-2025-38352","stars":119,"created":"2025-12-21"},{"name":"AnalyticETH/chronomaly-webos","url":"https://github.com/AnalyticETH/chronomaly-webos","stars":17,"created":"2026-05-30"},{"name":"jordelmir/Elysium-Vanguard-Sentinel-Audit","url":"https://github.com/jordelmir/Elysium-Vanguard-Sentinel-Audit","stars":2,"created":"2026-02-24"},{"name":"longwasu/CVE-2025-38352-PoC","url":"https://github.com/longwasu/CVE-2025-38352-PoC","stars":0,"created":"2026-09-13"}]},"first":{"date":"2025-12-21","source":"PoC-in-GitHub","url":"https://github.com/farazsth98/poc-CVE-2025-38352"},"provenance":"source"},"exploitRefs":["https://github.com/farazsth98/chronomaly"],"flow":[],"timeline":[{"date":"2025-07-22","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38352","provenance":"source"},{"date":"2025-09-01","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","provenance":"source"},{"date":"2025-09-04","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-09-04","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-22297","provenance":"source"},{"date":"2025-12-21","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/farazsth98/poc-CVE-2025-38352","provenance":"source"}],"speed":{"daysToPublicExploit":152,"firstExploitFrom":"PoC-in-GitHub","daysToKev":44},"priority":{"score":62.8,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 424 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":14.32,"detail":"percentile 0.7159"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit; 5 PoC-in-GitHub repos"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.46,"detail":"base score 7.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}