{"id":"CVE-2026-89642","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: call pagecache_isize_extended() in cifs_setsize() when extending\n\ncifs_setsize() calls truncate_pagecache() but skips\npagecache_isize_extended() on extension","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: call pagecache_isize_extended() in cifs_setsize() when extending\n\ncifs_setsize() calls truncate_pagecache() but skips\npagecache_isize_extended() on extension.  tr…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-201"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < e1f692b6da3e632a25d0b3a99f833bb609bae1a3","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 12bafe32f09c0d24f5096154b59c347b9c6606e0","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c510edb9734af1c274d18f4f31a471a166bbc7e8","Linux 2.6.12"],"published":"2026-09-11","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:54.727","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89642","references":[{"url":"https://git.kernel.org/stable/c/12bafe32f09c0d24f5096154b59c347b9c6606e0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c510edb9734af1c274d18f4f31a471a166bbc7e8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e1f692b6da3e632a25d0b3a99f833bb609bae1a3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89642.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89642"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532207"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89642"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89642"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89642.mbox"},{"url":"https://git.kernel.org/stable/c/5463d96cd2e46064ceefcf861b028745a4f4c373"},{"url":"https://git.kernel.org/stable/c/40c16040783abcc240bd1b453e679ea6ca30e19e"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00209,"epssPercentile":0.10966,"cvssSource":"vendor","ingestedAt":"2026-09-14T15:23:07.476Z","slug":"CVE-2026-89642","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncifs: call pagecache_isize_extended() in cifs_setsize() when extending\n\ncifs_setsize() calls truncate_pagecache() but skips\npagecache_isize_extended() on extension.  truncate_setsize() shows\nthe correct pattern:\n\n  i_size_write(inode, newsize);\n  if (newsize > oldsize)\n      pagecache_isize_extended(inode, oldsize, newsize);\n  truncate_pagecache(inode, newsize);\n\npagecache_isize_extended() zeroes the tail of the page straddling old\nEOF.  Without it, dirty bytes in that region can be written back to\nthe server, exposing stale data in the newly extended range.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89642.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":206925,"id":"CVE-2026-89642","ts":1789749703062,"field":"cvss","old":"6.5","new":"7"},{"seq":206924,"id":"CVE-2026-89642","ts":1789749703062,"field":"severity","old":"medium","new":"high"},{"seq":204057,"id":"CVE-2026-89642","ts":1789490231229,"field":"cvss","old":null,"new":"6.5"},{"seq":204056,"id":"CVE-2026-89642","ts":1789490231229,"field":"severity","old":"none","new":"medium"},{"seq":147550,"id":"CVE-2026-89642","ts":1789270211347,"field":"cvss","old":null,"new":"6.5"},{"seq":147549,"id":"CVE-2026-89642","ts":1789270211347,"field":"severity","old":"none","new":"medium"},{"seq":109302,"id":"CVE-2026-89642","ts":1789183731345,"field":"cvss","old":null,"new":"6.5"},{"seq":109301,"id":"CVE-2026-89642","ts":1789183731345,"field":"severity","old":"none","new":"medium"}]}