Linux Kernel up to 6.4.9 fs privilege escalation

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4.4	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.4.252/5.10.189/5.15.125/6.1.44/6.4.9. It has been declared as problematic. Affected by this issue is some unknown functionality of the component fs. The manipulation results in an unknown weakness. This vulnerability is cataloged as CVE-2023-54099. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.252/5.10.189/5.15.125/6.1.44/6.4.9. It has been classified as problematic. Affected is some unknown processing of the component fs. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fs: Protect reconfiguration of sb read-write from racing writes The reconfigure / remount code takes a lot of effort to protect filesystem's reconfiguration code from racing writes on remounting read-only. However during remounting read-only filesystem to read-write mode userspace writes can start immediately once we clear SB_RDONLY flag. This is inconvenient for example for ext4 because we need to do some writes to the filesystem (such as preparation of quota files) before we can take userspace writes so we are clearing SB_RDONLY flag before we are fully ready to accept userpace writes and syzbot has found a way to exploit this [1]. Also as far as I'm reading the code the filesystem remount code was protected from racing writes in the legacy mount path by the mount's MNT_READONLY flag so this is relatively new problem. It is actually fairly easy to protect remount read-write from racing writes using sb->s_readonly_remount flag so let's just do that instead of having to workaround these races in the filesystem code. [1] https://lore.kernel.org/all/[email protected]/T/

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2023-54099 since 12/24/2025. The exploitability is told to be difficult. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/03/2026).

The vulnerability scanner Nessus provides a plugin with the ID 279899 (Linux Distros Unpatched Vulnerability : CVE-2023-54099), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.253, 5.10.190, 5.15.126, 6.1.45 or 6.4.10 eliminates this vulnerability. Applying the patch 0336b42456e485fda1006b5b411e7372e20fbf03/7e4e87ec56aa6d008c64eab31b340a7c452b26cc/0ccfe21949bc9f706a86ee7351b74375c0745757/295ef44a2abaf97d7a594b1d4c60d4be3738191f/4abda85197ba5d695e6040d580b4b409ce0d3733/c541dce86c537714b6761a79a969c1623dfa222b is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (279899) and CERT Bund (WID-SEC-2025-2929). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.252
• 5.10.189
• 5.15.125
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.1.42
• 6.1.43
• 6.1.44
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6
• 6.4.7
• 6.4.8
• 6.4.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.4

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 279899
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-54099

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.253/5.10.190/5.15.126/6.1.45/6.4.10
Patch: 0336b42456e485fda1006b5b411e7372e20fbf03/7e4e87ec56aa6d008c64eab31b340a7c452b26cc/0ccfe21949bc9f706a86ee7351b74375c0745757/295ef44a2abaf97d7a594b1d4c60d4be3738191f/4abda85197ba5d695e6040d580b4b409ce0d3733/c541dce86c537714b6761a79a969c1623dfa222b

Timelineinfo

12/24/2025 Advisory disclosed
12/24/2025 +0 days CVE reserved
12/24/2025 +0 days VulDB entry created
01/03/2026 +9 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-54099 (🔒)
GCVE (CVE): GCVE-0-2023-54099
GCVE (VulDB): GCVE-100-338064
CERT Bund: WID-SEC-2025-2929 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/24/2025 15:02
Updated: 01/03/2026 00:07
Changes: 12/24/2025 15:02 (56), 12/26/2025 18:11 (2), 01/03/2026 00:07 (7)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion

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