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Fencer Vulns
no cvss —

CVE-2026-89642 json

cifs: call pagecache_isize_extended() in cifs_setsize() when extending

published 2026-09-11 58 d ago modified 2026-10-30 10 d ago also EUVD-2026-76554

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

cifs: call pagecache_isize_extended() in cifs_setsize() when extending

cifs_setsize() calls truncate_pagecache() but skips pagecache_isize_extended() on extension. truncate_setsize() shows the correct pattern:

i_size_write(inode, newsize); if (newsize > oldsize) pagecache_isize_extended(inode, oldsize, newsize); truncate_pagecache(inode, newsize);

pagecache_isize_extended() zeroes the tail of the page straddling old EOF. Without it, dirty bytes in that region can be written back to the server, exposing stale data in the newly extended range.

Patch / fix

  • Linux Linux 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.2.4, 7.3
  • linux Debian 13 6.12.115-2
  • linux Debian 14 7.2.6-1

debian advisories DEBIAN-CVE-2026-89642

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-89642

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
  • kernel-syms SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.339.1
  • kernel-source SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.339.1
  • kernel-default SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS, SLE Live Patching 12 SP5 4.12.14-122.339.1
  • kgraft-patch-SLE12-SP5_Update_90 SLE Live Patching 12 SP5 1-8.3.1

suse advisories SUSE-SU-2026:5121-1SUSE-SU-2026:24550-1

  • kernel-source openSUSE Tumbleweed 7.2.7-1.1

opensuse advisories openSUSE-SU-2026:11880-1

  • kernel Azure Linux 3.0 6.6.161.1-1

azure linux advisories AZL-100884

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-89642 updated cvss 3.3

kernel: cifs: call pagecache_isize_extended() in cifs_setsize() when extending

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.