CVE-2026-98215

Incorrect mprotect denial via nested backing-file SID

Published Oct 6, 2026 · Updated Oct 6, 2026

SELinux access-control errors in Linux with nested backing files cause local users' mprotect calls to fail under enforcing policy. In selinux_backing_file_alloc, the kernel copies an intermediate backing file's mounter SID into uf_sid instead of preserving the top-level opener's SID, so a later fd { use } check targets the wrong identity. The demonstrated failure requires SELinux enforcement and nested overlayfs mounts; it denies PROT_READ with EACCES, without demonstrating data theft or code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SELinux access-control errors in Linux with nested backing files cause local users' mprotect calls to fail under enforcing policy. In selinux_backing_file_alloc, the kernel copies an intermediate backing file's mounter SID into uf_sid instead of preserving the top-level opener's SID, so a later fd { use } check targets the wrong identity. The demonstrated failure requires SELinux enforcement and nested overlayfs mounts; it denies PROT_READ with EACCES, without demonstrating data theft or code execution.

The record

CVE
CVE-2026-98215
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.12.95 <6.12.112
  2. Affected versionversion=6.18.38 <6.18.54
  3. Affected versionversion=6.6.144 <6.6.158
  4. Affected versionversion=7.0.4 <7.1
  5. Affected versionversion=7.1
  6. Affected versionversion=82544d36b1729153c8aeb179e84750f0c085d3b1 <8c0c602202b9a4909b00bc3354e3c0355bc69e65
  7. Affected versionversion=82544d36b1729153c8aeb179e84750f0c085d3b1 <ff20d16b2e8230c034e21540043df47222dcc09b
  8. Affected versionversion=8bacd09f12c27710228562e4d13163e58c5f4a45 <6aaeec59aadcd1eafc18b049f1b759fb6b9d9569
  9. Affected versionversion=bc6c380c1159de52a252ed11f19a42c47f60a735 <caa1b913d90d5dc07073733326d2af0f0288f089
  10. Affected versionversion=cd0e707a927a70cdfd8bc5a512a9719a87f5ed51
  11. Affected versionversion=d844702198395d3f80222777030f69db6be6b709 <9d99b770e7b67b00bdef9005b928aad13e1d679b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.12.95 <6.12.112; version=6.18.38 <6.18.54; version=6.6.144 <6.6.158; version=7.0.4 <7.1; version=7.1; version=82544d36b1729153c8aeb179e84750f0c085d3b1 <8c0c602202b9a4909b00bc3354e3c0355bc69e65; version=82544d36b1729153c8aeb179e84750f0c085d3b1 <ff20d16b2e8230c034e21540043df47222dcc09b; version=8bacd09f12c27710228562e4d13163e58c5f4a45 <6aaeec59aadcd1eafc18b049f1b759fb6b9d9569; version=bc6c380c1159de52a252ed11f19a42c47f60a735 <caa1b913d90d5dc07073733326d2af0f0288f089; version=cd0e707a927a70cdfd8bc5a512a9719a87f5ed51; version=d844702198395d3f80222777030f69db6be6b709 <9d99b770e7b67b00bdef9005b928aad13e1d679b

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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