CVE-2025-39728

Kernel crash via premature clock-array dereference

Published Apr 18, 2025 · Updated May 11, 2026

Out-of-bounds array access in the Linux kernel allows local users to trigger a kernel crash during Samsung clock setup. In samsung_clk_init(), the hardware-clock array is populated while clk_data.num is still zero because the count is assigned only after the loop. Reachability requires Samsung clock-provider initialization, and UBSAN_ARRAY_BOUNDS exposes the faulty access as a panic; no data disclosure or modification is reported.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds array access in the Linux kernel allows local users to trigger a kernel crash during Samsung clock setup. In samsung_clk_init(), the hardware-clock array is populated while clk_data.num is still zero because the count is assigned only after the loop. Reachability requires Samsung clock-provider initialization, and UBSAN_ARRAY_BOUNDS exposes the faulty access as a panic; no data disclosure or modification is reported.

The record

CVE
CVE-2025-39728
Published
Apr 18, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-129, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 18, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=5.5
  2. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <00307934eb94aaa0a99addfb37b9fe206f945004
  3. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <0fef48f4a70e45a93e73c39023c3a6ea624714d6
  4. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <157de9e48007a20c65d02fc0229a16f38134a72d
  5. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <24307866e0ac0a5ddb462e766ceda5e27a6fbbe3
  6. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <4d29a6dcb51e346595a15b49693eeb728925ca43
  7. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <a1500b98cd81a32fdfb9bc63c33bb9f0c2a0a1bf
  8. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <d19d7345a7bcdb083b65568a11b11adffe0687af
  9. Affected versionversion=e620a1e061c4738e26c3edf2abaae7842532cd80 <d974e177369c034984cece9d7d4fada9f8b9c740

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <00307934eb94aaa0a99addfb37b9fe206f945004; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <0fef48f4a70e45a93e73c39023c3a6ea624714d6; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <157de9e48007a20c65d02fc0229a16f38134a72d; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <24307866e0ac0a5ddb462e766ceda5e27a6fbbe3; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <4d29a6dcb51e346595a15b49693eeb728925ca43; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <a1500b98cd81a32fdfb9bc63c33bb9f0c2a0a1bf; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <d19d7345a7bcdb083b65568a11b11adffe0687af; version=e620a1e061c4738e26c3edf2abaae7842532cd80 <d974e177369c034984cece9d7d4fada9f8b9c740

Published CVSS scores

5.5CISA ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
T1499.004Application or System Exploitation

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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Your stack

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