CVE-2025-39994

Local privilege escalation via xc5000 teardown race

Published Oct 15, 2025 · Updated Oct 15, 2025

Use-after-free in the Linux kernel xc5000 tuner driver allows local users to execute code in kernel context during driver teardown. xc5000_release calls cancel_delayed_work, then frees xc5000_priv without waiting for an already-running timer_sleep callback, which subsequently dereferences the freed object. Exploitation requires an accessible DVB or V4L2 tuner node and a separate administrator removal, module unload, or physical tuner disconnection during the primed callback window.

CVSS severity7.3
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel xc5000 tuner driver allows local users to execute code in kernel context during driver teardown. xc5000_release calls cancel_delayed_work, then frees xc5000_priv without waiting for an already-running timer_sleep callback, which subsequently dereferences the freed object. Exploitation requires an accessible DVB or V4L2 tuner node and a separate administrator removal, module unload, or physical tuner disconnection during the primed callback window.

The record

CVE
CVE-2025-39994
Published
Oct 15, 2025
Updated
Oct 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=3.16
  2. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <40b7a19f321e65789612ebaca966472055dab48c
  3. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <4266f012806fc18e46da4a04d130df59a4946f93
  4. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <71ed8b81a4906cb785966910f39cf7f5ad60a69e
  5. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <9a00de20ed8ba90888479749b87bc1532cded4ce
  6. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <df0303b4839520b84d9367c2fad65b13650a4d42
  7. Affected versionversion=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <effb1c19583bca7022fa641a70766de45c6d41ac

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.16; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <40b7a19f321e65789612ebaca966472055dab48c; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <4266f012806fc18e46da4a04d130df59a4946f93; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <71ed8b81a4906cb785966910f39cf7f5ad60a69e; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <9a00de20ed8ba90888479749b87bc1532cded4ce; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <df0303b4839520b84d9367c2fad65b13650a4d42; version=f7a27ff1fb77e114d1059a5eb2ed1cffdc508ce8 <effb1c19583bca7022fa641a70766de45c6d41ac

Published CVSS scores

7.3Linux kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/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

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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