{"id":"CVE-2026-89639","title":"kernel: cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC (CVE-2026-89639)","summary":"A flaw was found in the Linux kernel's Common Internet File System (CIFS) implementation. When a file is truncated, the `cifs_do_truncate()` function does not properly invalidate the file system cache (fscache). This oversight can lead to …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-524","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","affected":["enterprise_linux 10"],"published":"2026-09-11","updated":"2026-09-16","sourceUpdated":"2026-09-16T14:15:00+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89639.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89639.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89639"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532382"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89639"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89639"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89639.mbox"},{"url":"https://git.kernel.org/stable/c/364b183230586a62660a7280c1eb20138338eeb5"},{"url":"https://git.kernel.org/stable/c/81fc3868a7f726980ff845c1d0d271051e5f0f45"},{"url":"https://git.kernel.org/stable/c/8b9b10fe5b8b492b27b9f4546742ea541a650213"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00124,"epssPercentile":0.02505,"scores":{"vendor":3.3,"cna":7.1},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89639","body":"## Overview\n\nA flaw was found in the Linux kernel's Common Internet File System (CIFS) implementation. When a file is truncated, the `cifs_do_truncate()` function does not properly invalidate the file system cache (fscache). This oversight can lead to stale cached data being served to users, potentially resulting in information disclosure or data inconsistency.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89639.json)\n\n**kernel: cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205438,"id":"CVE-2026-89639","ts":1789576713916,"field":"cvss","old":"3.3","new":"5.5"},{"seq":205437,"id":"CVE-2026-89639","ts":1789576713916,"field":"severity","old":"low","new":"medium"},{"seq":202812,"id":"CVE-2026-89639","ts":1789403731311,"field":"cvss","old":"7.1","new":"3.3"},{"seq":202811,"id":"CVE-2026-89639","ts":1789403731311,"field":"severity","old":"high","new":"low"},{"seq":197821,"id":"CVE-2026-89639","ts":1789384320541,"field":"cvss","old":"3.3","new":"7.1"},{"seq":197820,"id":"CVE-2026-89639","ts":1789384320541,"field":"severity","old":"low","new":"high"},{"seq":183331,"id":"CVE-2026-89639","ts":1789356674897,"field":"cvss","old":"7.1","new":"3.3"},{"seq":183330,"id":"CVE-2026-89639","ts":1789356674897,"field":"severity","old":"high","new":"low"},{"seq":153482,"id":"CVE-2026-89639","ts":1789285350695,"field":"cvss","old":null,"new":"7.1"},{"seq":153481,"id":"CVE-2026-89639","ts":1789285350695,"field":"severity","old":"none","new":"high"},{"seq":147289,"id":"CVE-2026-89639","ts":1789270207313,"field":"cvss","old":null,"new":"3.3"},{"seq":147288,"id":"CVE-2026-89639","ts":1789270207313,"field":"severity","old":"none","new":"low"},{"seq":109044,"id":"CVE-2026-89639","ts":1789183730086,"field":"cvss","old":null,"new":"3.3"},{"seq":109043,"id":"CVE-2026-89639","ts":1789183730086,"field":"severity","old":"none","new":"low"}]}