CVE-2025-71066VulnerabilityPublished 15 Apr 2026

ZDI-26-289: Linux Kernel ETS Scheduler Race Condition Local Privilege Escalation Vulnerability

Source Zero Day Initiative

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Not known to be exploited.

Data as of 29 Oct 2026, 19:04 UTC

Severity

High

Rated High by Zero Day Initiative · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
Public on cve.org; its publication date is not in this record
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Linux has issued an official update to correct this vulnerability. Applying the vendor-provided patch or updated kernel version is the recommended remediation. Since this is a local privilege escalation requiring prior high-privilege code execution, ensuring systems are updated will prevent exploitation. No additional mitigations are specified in the advisory.

Description

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2025-71066.

Impact

This vulnerability enables local attackers with existing high-privilege code execution to escalate their privileges further and execute arbitrary code in kernel context. This can lead to complete system compromise, including confidentiality, integrity, and availability impacts. The high CVSS score reflects the significant impact on affected systems if exploited.

Summary

CVE-2025-71066 is a local privilege escalation vulnerability in the Linux Kernel related to a race condition in the ETS scheduler's handling of Qdisc objects. The vulnerability stems from a lack of proper locking during operations on these objects, which can be exploited by an attacker who already has the ability to execute high-privileged code on the system. Successful exploitation allows escalation of privileges and arbitrary code execution within the kernel. The Zero Day Initiative assigned a CVSS score of 7.5 (AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H). Linux has released an update to fix this issue, as documented in the vendor advisory and linked kernel patch mailing list post.

References

zerodayinitiative.com/advisories/ZDI-26-289/ (opens in a new tab)

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