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NVD / CVE Program· CNA Linux

CVE-2025-38539: tracing: Add down_write(trace_event_sem) when adding trace event

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 33e20747b47ddc03569b6bc27a2d6894c1428182, 6bc94f20a4c304997288f9a45278c9d0c06987d3, 70fecd519caad0c1741c3379d5348c9000a5b29d; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 33e20747b47ddc03569b6bc27a2d6894c1428182, 6bc94f20a4c304997288f9a45278c9d0c06987d3, 70fecd519caad0c1741c3379d5348c9000a5b29d; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Aug 16, 2025
Updated
Oct 15, 2026
EPSS
0.1% · 8th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.8
2.3 point gap

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux11.0
  • linux linux kernel5.5 and later · before 5.10.241
  • linux linux kernel5.11 and later · before 5.15.190
  • linux linux kernel5.16 and later · before 6.1.147
  • linux linux kernel2.6.31 and later · before 5.4.297
  • linux linux kernel6.7 and later · before 6.12.40
  • linux linux kernel6.13 and later · before 6.15.8
  • linux linux kernel6.2 and later · before 6.6.100
  • linux linux kernel6.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.31affected
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before e70f5ee4c8824736332351b703c46f9469ed7f6caffected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before db45632479ceecb669612ed8dbce927e3c6279fcaffected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before ca60064ea03f14e06c763de018403cb56ba3207daffected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before 7803b28c9aa8d8bd4e19ebcf5f0db9612b0f333baffected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before 6bc94f20a4c304997288f9a45278c9d0c06987d3affected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before 33e20747b47ddc03569b6bc27a2d6894c1428182affected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before 70fecd519caad0c1741c3379d5348c9000a5b29daffected · git
    • 110bf2b764eb6026b868d84499263cb24b1bcc8d and later · before b5e8acc14dcb314a9b61ff19dcd9fdd0d88f70dfaffected · git
    • before 2.6.31not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.147-16.1.147-1
Debian:13linuxbefore 6.12.41-16.12.41-1
Debian:14linuxbefore 6.16.3-16.16.3-1
openSUSE:Leap 15.6dtb-aarch64before 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-64kbbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-debugbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-defaultbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-default-basebefore 6.4.0-150600.23.87.1.150600.12.40.16.4.0-150600.23.87.1.150600.12.40.1
openSUSE:Leap 15.6kernel-docsbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-kvmsmallbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-obs-buildbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-obs-qabefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-sourcebefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-symsbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
openSUSE:Leap 15.6kernel-zfcpdumpbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
SUSE:Linux Enterprise Live Patching 15 SP6kernel-defaultbefore 6.4.0-150600.23.87.16.4.0-150600.23.87.1
SUSE:Linux Enterprise Live Patching 15 SP6kernel-livepatch-SLE15-SP6_Update_20before 1-150600.13.3.11-150600.13.3.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_9before 1-150700.15.3.11-150700.15.3.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7-RT_Update_9before 1-150700.1.3.21-150700.1.3.2
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.31.16.4.0-150700.53.31.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-defaultbefore 6.4.0-150700.53.31.16.4.0-150700.53.31.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-default-basebefore 6.4.0-150700.53.31.1.150700.17.21.16.4.0-150700.53.31.1.150700.17.21.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-sourcebefore 6.4.0-150700.53.31.16.4.0-150700.53.31.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-zfcpdumpbefore 6.4.0-150700.53.31.16.4.0-150700.53.31.1

+16

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-38535Aug 16, 2025 · phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode
    31Monitor
  • ← EarlierCVE-2025-38537Aug 16, 2025 · net: phy: Don't register LEDs for genphy
    22Monitor
  • Later →CVE-2025-38540Aug 16, 2025 · HID: quirks: Add quirk for 2 Chicony Electronics HP 5MP Cameras
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux33e20747b47ddc03569b6bc27a2d6894c1428182Vendor (CNA)
Linux Linux6bc94f20a4c304997288f9a45278c9d0c06987d3Vendor (CNA)
Linux Linux70fecd519caad0c1741c3379d5348c9000a5b29dVendor (CNA)
Linux Linux7803b28c9aa8d8bd4e19ebcf5f0db9612b0f333bVendor (CNA)
Linux Linuxb5e8acc14dcb314a9b61ff19dcd9fdd0d88f70dfVendor (CNA)
Linux Linuxca60064ea03f14e06c763de018403cb56ba3207dVendor (CNA)
Linux Linuxdb45632479ceecb669612ed8dbce927e3c6279fcVendor (CNA)
Linux Linuxe70f5ee4c8824736332351b703c46f9469ed7f6cVendor (CNA)
azl3 kernel 6.6.96.2-2 on Azure Linux 3.06.6.104.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.05.15.200.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.147-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-64kb6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-debug6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default-base6.4.0-150600.23.87.1.150600.12.40.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-docs6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-kvmsmall6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-build6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-qa6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-source6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-syms6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-zfcpdump6.4.0-150600.23.87.1 · openSUSE:Leap 15.6Package registry (OSV)
suse:kernel-64kb6.4.0-150600.23.87.1 · SUSE:Linux Enterprise Server 15 SP6-LTSSPackage registry (OSV)
suse:kernel-64kb6.4.0-150700.53.31.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-azure6.4.0-150700.20.27.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP7Package registry (OSV)
suse:kernel-default6.4.0-150600.23.87.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-default6.4.0-150700.53.31.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default-base6.4.0-150600.23.87.1.150600.12.40.1 · SUSE:Linux Enterprise Server 15 SP6-LTSSPackage registry (OSV)
suse:kernel-default-base6.4.0-150700.53.31.1.150700.17.21.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)

+13

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records