Linux Kernel up to 7.3-rc3 SELinux mprotect vm_file access control

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. Affected is the function mprotect of the component SELinux. Such manipulation of the argument vm_file leads to access control. This vulnerability is documented as CVE-2026-98214. The attack needs to be performed locally. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. It has been rated as very critical. Affected by this issue is the function mprotect of the component SELinux. The manipulation of the argument vm_file with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: selinux: recheck intermediate backing files on mprotect() mprotect() can be used to bypass the SELinux checks that mmap() performs against the intermediate layers of a stacked filesystem. mmap() checks every backing layer as the request descends through the stack. mprotect() only has the lowest backing file in vma->vm_file, so it rechecks the top-level user and the lowest mounter, but skips the mounters of every layer in between. With two nested overlayfs mounts and a policy denying mounter_t -> middle_file_t:file { execute }, a direct mmap(PROT_EXEC) is denied: avc: denied { execute } for pid=71 comm="nested_exec" path="/payload" dev="overlay" ino=9 scontext=user_u:base_r:mounter_t tcontext=user_u:object_r:middle_file_t tclass=file permissive=0 while mmap(PROT_NONE) followed by mprotect(PROT_EXEC) succeeds. Preserve each intermediate path, mounter SID and file-description SID in the backing-file security blob, copying the saved entries when another backing layer is opened. Allocate the array only for nested backing files, and release it and the path references in the backing_file_free hook. During mprotect(), recheck fd { use } and the requested inode permissions for every saved mounter, and include the intermediate layers in the execmod checks. Policy for nested stacking may then need to grant intermediate mounters what a direct mmap() already requires, and execmod on intermediate labels for binaries using text relocations. Tested on arm64 QEMU with a small BusyBox initramfs and a purpose-built SELinux policy, on a mainline tree containing commit f2381b546e7e ("fs: fix user path of nested backing files"). [PM: subject tweak]

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-98214 since 09/25/2026. The exploitation is known to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/06/2026). The MITRE ATT&CK project declares the attack technique as T1068.

Upgrading to version 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 4d50ebe5a27724e020747ffd61a051dec67cb8ec/89376fbfdcc1a728e1775f98752cdd90b0930a00/d127c7e1f3e1231d8ac8b2738e3f00bea12afe74/c2bbb905af2293549651b614a52ad91e0b462b60/78fc54b934bfb2c18aad8154c7302067146946f9 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.158/6.12.112/6.18.54/7.2.8/7.3-rc4
Patch: 4d50ebe5a27724e020747ffd61a051dec67cb8ec/89376fbfdcc1a728e1775f98752cdd90b0930a00/d127c7e1f3e1231d8ac8b2738e3f00bea12afe74/c2bbb905af2293549651b614a52ad91e0b462b60/78fc54b934bfb2c18aad8154c7302067146946f9

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CNA: Linux
CVE: CVE-2026-98214 (🔒)

GCVE (CVE): GCVE-0-2026-98214
GCVE (VulDB): GCVE-100-414116

Entryinfo

Created: 10/06/2026 12:54
Changes: 10/06/2026 12:54 (60)
Complete: 🔍
Cache ID: 216::103

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