CVE-2025-21695

System crash via premature serdev port activation

Published Feb 12, 2025 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel allows local users to crash affected Dell systems during UART backlight initialization. dell_uart_bl_serdev_probe opens the serdev device before installing client operations, so receive_buf can dereference a null ops pointer after the port becomes active. The race affects 6.10 through 6.12.10 and 6.13-rc1 through 6.13-rc7 and requires low-privileged local access plus the Dell UART backlight driver path; the bounded consequence is a system crash.

CVSS severity4.7
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel allows local users to crash affected Dell systems during UART backlight initialization. dell_uart_bl_serdev_probe opens the serdev device before installing client operations, so receive_buf can dereference a null ops pointer after the port becomes active. The race affects 6.10 through 6.12.10 and 6.13-rc1 through 6.13-rc7 and requires low-privileged local access plus the Dell UART backlight driver path; the bounded consequence is a system crash.

The record

CVE
CVE-2025-21695
Published
Feb 12, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 12, 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=484bae9e4d6acb5eec39e1ea47f9aa43f11b154d <1b2128aa2d45ab20b22548dcf4b48906298ca7fd
  2. Affected versionversion=484bae9e4d6acb5eec39e1ea47f9aa43f11b154d <d3a24d923333f75aaece9acb051d676edc0afb75
  3. Affected versionversion=6.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=484bae9e4d6acb5eec39e1ea47f9aa43f11b154d <1b2128aa2d45ab20b22548dcf4b48906298ca7fd; version=484bae9e4d6acb5eec39e1ea47f9aa43f11b154d <d3a24d923333f75aaece9acb051d676edc0afb75; version=6.10

Published CVSS scores

4.7CISA-ADPCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS: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-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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