Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7 tracing lockdep_assert_held format string

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6.6	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7. It has been classified as critical. Affected by this issue is the function lockdep_assert_held of the component tracing. Performing a manipulation results in format string. This vulnerability is cataloged as CVE-2025-38539. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7. This affects the function lockdep_assert_held of the component tracing. The manipulation with an unknown input leads to a format string vulnerability. CWE is classifying the issue as CWE-134. The product uses a function that accepts a format string as an argument, but the format string originates from an external source. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: tracing: Add down_write(trace_event_sem) when adding trace event When a module is loaded, it adds trace events defined by the module. It may also need to modify the modules trace printk formats to replace enum names with their values. If two modules are loaded at the same time, the adding of the event to the ftrace_events list can corrupt the walking of the list in the code that is modifying the printk format strings and crash the kernel. The addition of the event should take the trace_event_sem for write while it adds the new event. Also add a lockdep_assert_held() on that semaphore in __trace_add_event_dirs() as it iterates the list.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-38539 since 04/16/2025. The exploitability is told to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 259990 (Linux Distros Unpatched Vulnerability : CVE-2025-38539), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.147, 6.6.100, 6.12.40 or 6.15.8 eliminates this vulnerability. Applying the patch 7803b28c9aa8d8bd4e19ebcf5f0db9612b0f333b/6bc94f20a4c304997288f9a45278c9d0c06987d3/33e20747b47ddc03569b6bc27a2d6894c1428182/70fecd519caad0c1741c3379d5348c9000a5b29d/b5e8acc14dcb314a9b61ff19dcd9fdd0d88f70df 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 (259990), EUVD (EUVD-2025-26108) and CERT Bund (WID-SEC-2025-1858). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM
• IBM Security Verify Access

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.146
• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.6.60
• 6.6.61
• 6.6.62
• 6.6.63
• 6.6.64
• 6.6.65
• 6.6.66
• 6.6.67
• 6.6.68
• 6.6.69
• 6.6.70
• 6.6.71
• 6.6.72
• 6.6.73
• 6.6.74
• 6.6.75
• 6.6.76
• 6.6.77
• 6.6.78
• 6.6.79
• 6.6.80
• 6.6.81
• 6.6.82
• 6.6.83
• 6.6.84
• 6.6.85
• 6.6.86
• 6.6.87
• 6.6.88
• 6.6.89
• 6.6.90
• 6.6.91
• 6.6.92
• 6.6.93
• 6.6.94
• 6.6.95
• 6.6.96
• 6.6.97
• 6.6.98
• 6.6.99
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3
• 6.15.4
• 6.15.5
• 6.15.6
• 6.15.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Format string
CWE: CWE-134 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 259990
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-38539

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.147/6.6.100/6.12.40/6.15.8
Patch: 7803b28c9aa8d8bd4e19ebcf5f0db9612b0f333b/6bc94f20a4c304997288f9a45278c9d0c06987d3/33e20747b47ddc03569b6bc27a2d6894c1428182/70fecd519caad0c1741c3379d5348c9000a5b29d/b5e8acc14dcb314a9b61ff19dcd9fdd0d88f70df

Timelineinfo

04/16/2025 CVE reserved
08/16/2025 +122 days Advisory disclosed
08/16/2025 +0 days VulDB entry created
01/30/2026 +167 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38539 (🔒)
GCVE (CVE): GCVE-0-2025-38539
GCVE (VulDB): GCVE-100-320409
EUVD: 🔒
CERT Bund: WID-SEC-2025-1858 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 08/16/2025 18:05
Updated: 01/30/2026 20:20
Changes: 08/16/2025 18:05 (60), 09/01/2025 06:31 (2), 09/28/2025 09:43 (7), 10/03/2025 14:32 (1), 10/12/2025 18:53 (1), 11/01/2025 19:49 (1), 01/07/2026 20:08 (12), 01/08/2026 20:38 (1), 01/30/2026 20:20 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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