{"id":"CVE-2025-39689","title":"kernel: ftrace: Also allocate and copy hash for reading of filter files (CVE-2025-39689)","summary":"A flaw was found in the Linux kernel. A Use-After-Free (UAF) vulnerability exists in the ftrace subsystem during the reading of tracing filter files. The filter reader retains a direct pointer to global filter data rather than creating an …","severity":"medium","cvss":6.4,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-694","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 8","enterprise_linux 9"],"published":"2025-09-05","updated":"2026-10-16","sourceUpdated":"2026-10-16T22:56:04+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39689.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39689.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-39689"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2393517"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-39689"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39689"},{"url":"https://lore.kernel.org/linux-cve-announce/2025090546-CVE-2025-39689-f538@gregkh/T"},{"url":"https://git.kernel.org/stable/c/12064e1880fc9202be75ff668205b1703d92f74f"},{"url":"https://git.kernel.org/stable/c/c4cd93811e038d19f961985735ef7bb128078dfb"},{"url":"https://git.kernel.org/stable/c/e0b6b223167e1edde5c82edf38e393c06eda1f13"},{"url":"https://git.kernel.org/stable/c/a40c69f4f1ed96acbcd62e9b5ff3a596f0a91309"},{"url":"https://git.kernel.org/stable/c/3b114a3282ab1a12cb4618a8f45db5d7185e784a"},{"url":"https://git.kernel.org/stable/c/c591ba1acd081d4980713e47869dd1cc3d963d19"},{"url":"https://git.kernel.org/stable/c/64db338140d2bad99a0a8c6a118dd60b3e1fb8cb"},{"url":"https://git.kernel.org/stable/c/bfb336cf97df7b37b2b2edec0f69773e06d11955"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00184,"epssPercentile":0.07953,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:53:25.266469Z"},"scores":{"vendor":6.4,"cna":7.8},"ingestedAt":"2026-10-15T05:52:46.080Z","slug":"CVE-2025-39689","body":"## Overview\n\nA flaw was found in the Linux kernel. A Use-After-Free (UAF) vulnerability exists in the ftrace subsystem during the reading of tracing filter files. The filter reader retains a direct pointer to global filter data rather than creating an independent copy, which allows concurrent updates to free the underlying memory while it is still referenced. A local attacker can exploit this flaw to cause a Denial of Service (DoS) through a system crash or potentially achieve privilege escalation.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39689.json)\n\n**kernel: ftrace: Also allocate and copy hash for reading of filter files** — rated Moderate by Red Hat. Released 2025-09-05, updated 2026-10-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n\nNot affected:\n\n- Red Hat Enterprise Linux 7\n\n## Remediation\n\nOut of support scope\n\nWorkarounds / mitigations:\n\n- Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":35.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":223719,"id":"CVE-2025-39689","ts":1792238376017,"field":"cvss","old":"7.8","new":"6.4"},{"seq":223718,"id":"CVE-2025-39689","ts":1792238376017,"field":"severity","old":"high","new":"medium"}]}