<Vulnerability name="CVE-2026-89683">
    <DocumentDistribution xml:lang="en">Copyright © 2012 Red Hat, Inc. All rights reserved.</DocumentDistribution>
    <ThreatSeverity>Moderate</ThreatSeverity>
    <PublicDate>2026-09-11T00:00:00</PublicDate>
    <Bugzilla id="2532313" url="https://bugzilla.redhat.com/show_bug.cgi?id=2532313" xml:lang="en:us">
kernel: nfsd: fix dentry ref leak on V4ROOT export filehandle lookup
    </Bugzilla>
    <CVSS3 status="draft">
        <CVSS3BaseScore>7.0</CVSS3BaseScore>
        <CVSS3ScoringVector>CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H</CVSS3ScoringVector>
    </CVSS3>
    <CWE>CWE-911</CWE>
    <Details xml:lang="en:us" source="Mitre">
In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix dentry ref leak on V4ROOT export filehandle lookup

nfsd_set_fh_dentry() leaks the dentry reference from
exportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_FHSIZE
switch cases detect NFSEXP_V4ROOT and goto out. The out: label
calls exp_put() but never dput(dentry), and fhp-&gt;fh_dentry was
never assigned so fh_put() cannot compensate.

A crafted NFSv3 filehandle targeting a V4ROOT export's fsid
triggers the leak on every request.
    </Details>
    <Details xml:lang="en:us" source="Red Hat">
A flaw was found in the Linux kernel's nfsd (NFS daemon). A remote attacker could exploit this vulnerability by sending a specially crafted NFSv3 filehandle targeting a V4ROOT export's file system identifier (fsid). This action triggers a dentry reference leak, which can lead to resource exhaustion and ultimately result in a Denial of Service (DoS) on the affected system.
    </Details>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:10">
        <ProductName>Red Hat Enterprise Linux 10</ProductName>
        <FixState>Affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:10">
        <ProductName>Red Hat Enterprise Linux 10</ProductName>
        <FixState>Affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:6">
        <ProductName>Red Hat Enterprise Linux 6</ProductName>
        <FixState>Out of support scope</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/a:redhat:openshift:4">
        <ProductName>Red Hat OpenShift Container Platform 4</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>openshift/ose-rhel-coreos-8</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/a:redhat:openshift:4">
        <ProductName>Red Hat OpenShift Container Platform 4</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>openshift/ose-rhel-coreos-9</PackageName>
    </PackageState>
    <References xml:lang="en:us">
https://www.cve.org/CVERecord?id=CVE-2026-89683
https://nvd.nist.gov/vuln/detail/CVE-2026-89683
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89683.mbox
    </References>
</Vulnerability>