CVE-2026-98215
N/AIn the Linux kernel, the following vulnerability has been resolved: selinux: preserve user SID across nested backing files SELinux saves the user file SID in a backing-file security blob so it remains available after mmap() replaces vma->vm_file with a backing file. For nested backing files (overlayfs over overlayfs, or FUSE passthrough backed by overlayfs), user_file may itself be a backing file. Its fsec->sid is the SID of the mounter that opened it, rather than the user that opened the top-level file. mprotect() then checks fd { use } against the mounter SID. This can incorrectly deny access without a domain transition, or check the wrong target SID after one. Copy the saved user SID when user_file is a backing file. Keep using the regular file SID for the first backing layer. With two nested overlayfs mounts and SELinux enforcing, mprotect(PROT_READ) returns EACCES with an fd { use } denial against the mounter SID. With this change, mprotect() succeeds. Tested on arm64 QEMU with a small BusyBox initramfs and a purpose-built SELinux policy. The original test was also repeated with Fedora Cloud Base 44 userspace and gave the same result.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 10th percentile
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept
No public PoC is currently catalogued.
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References and research data (JSON)
Vendor product assessments
Showing 32 of 278 vendor product statements; 246 omitted. Read the full vendor advisory.
kernel as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-debug as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-rt as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-rt-debug-kvm as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug-kvm
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-zfcpdump-devel as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump-devel
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-doc as a component of Red Hat Enterprise Linux 6 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-doc
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- no fix planned: Out of support scope
kernel-debug-modules as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug-modules
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-rt-debug-modules as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug-modules
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-zfcpdump-modules as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump-modules
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k-debug-modules-extra
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-debug-modules as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug-modules
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-modules-partner as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules-partner
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-rt-64k-kvm as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-kvm
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-rt-devel as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-devel
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
kernel-zfcpdump as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · known affected
Vendor assessment for this product only.
pkg:oci/ose-rhel-coreos-9?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9
- workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
- none available: Fix deferred
bpftool as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bpftool
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-abi-whitelists as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-abi-whitelists
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-debug as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-debug
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-debug-devel
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-doc as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-doc
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-kdump as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-kdump
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-debug-devel
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt-debug-kvm as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-debug-kvm
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-doc
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt-trace as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-trace
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-rt-trace-kvm as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-trace-kvm
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-tools as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel-tools-libs as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools-libs
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00kernel.src as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel?arch=src
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00python-perf as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/python-perf
Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
References
Advisories
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98215.json Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-93143 EUVD · EUVD-2026-93143
Technical & other
- https://git.kernel.org/stable/c/caa1b913d90d5dc07073733326d2af0f0288f089CVE record · Linux · Updated 2026-10-19T09:15:46.038Z
NVD · CVE-2026-98215 · Updated 2026-10-19T10:18:22.230 - https://git.kernel.org/stable/c/6aaeec59aadcd1eafc18b049f1b759fb6b9d9569CVE record · Linux · Updated 2026-10-19T09:15:46.038Z
NVD · CVE-2026-98215 · Updated 2026-10-19T10:18:22.230 - https://git.kernel.org/stable/c/9d99b770e7b67b00bdef9005b928aad13e1d679bCVE record · Linux · Updated 2026-10-19T09:15:46.038Z
NVD · CVE-2026-98215 · Updated 2026-10-19T10:18:22.230 - https://git.kernel.org/stable/c/ff20d16b2e8230c034e21540043df47222dcc09bCVE record · Linux · Updated 2026-10-19T09:15:46.038Z
NVD · CVE-2026-98215 · Updated 2026-10-19T10:18:22.230 - https://git.kernel.org/stable/c/8c0c602202b9a4909b00bc3354e3c0355bc69e65CVE record · Linux · Updated 2026-10-19T09:15:46.038Z
NVD · CVE-2026-98215 · Updated 2026-10-19T10:18:22.230 - https://access.redhat.com/security/cve/CVE-2026-98215 Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2546336 Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-98215 Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-98215 Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98215.mbox Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00
- https://kernelcve.org/list/?q=CVE-2026-98215 Red Hat · CVE-2026-98215 · Updated 2026-10-22T00:50:29+00:00