ZDI-26-575: Linux Kernel Net Scheduler Packet Classifier API Time-Of-Check Time-Of-Use Local Privilege Escalation Vulnerability
A local privilege escalation vulnerability exists in the Linux Kernel's Net Scheduler Packet Classifier API due to improper locking during object operations. Exploitation requires the attacker to already have the ability to execute high-privileged code on the target system. Successful exploitation allows escalation of privileges and execution of code in kernel context. Linux has issued an update to address this vulnerability.
AI Analysis
Technical Summary
This vulnerability (ZDI-26-575) affects the Linux Kernel's traffic classifier component within the Net Scheduler Packet Classifier API. The root cause is a time-of-check to time-of-use (TOCTOU) race condition resulting from a lack of proper locking when performing operations on an object. An attacker with existing high-privileged code execution capabilities can exploit this flaw to escalate privileges further and execute code in kernel context. The vulnerability has been assigned a CVSS score of 7.5 by the Zero Day Initiative, indicating high severity. Linux has released a patch to fix this issue, available at the referenced GitHub commit.
Potential Impact
The vulnerability enables local attackers who already have high-privileged code execution on the system to escalate their privileges further and execute code within the kernel context. This can lead to full system compromise or bypass of security controls enforced by the kernel.
Mitigation Recommendations
Linux has issued an official update that corrects this vulnerability. Users and administrators should apply the Linux Kernel update containing the fix referenced in the vendor advisory (https://github.com/torvalds/linux/commit/8b519cbcabe836a441369fbec1a8a6518a709251) to remediate this issue.
ZDI-26-575: Linux Kernel Net Scheduler Packet Classifier API Time-Of-Check Time-Of-Use Local Privilege Escalation Vulnerability
Description
A local privilege escalation vulnerability exists in the Linux Kernel's Net Scheduler Packet Classifier API due to improper locking during object operations. Exploitation requires the attacker to already have the ability to execute high-privileged code on the target system. Successful exploitation allows escalation of privileges and execution of code in kernel context. Linux has issued an update to address this vulnerability.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (ZDI-26-575) affects the Linux Kernel's traffic classifier component within the Net Scheduler Packet Classifier API. The root cause is a time-of-check to time-of-use (TOCTOU) race condition resulting from a lack of proper locking when performing operations on an object. An attacker with existing high-privileged code execution capabilities can exploit this flaw to escalate privileges further and execute code in kernel context. The vulnerability has been assigned a CVSS score of 7.5 by the Zero Day Initiative, indicating high severity. Linux has released a patch to fix this issue, available at the referenced GitHub commit.
Potential Impact
The vulnerability enables local attackers who already have high-privileged code execution on the system to escalate their privileges further and execute code within the kernel context. This can lead to full system compromise or bypass of security controls enforced by the kernel.
Mitigation Recommendations
Linux has issued an official update that corrects this vulnerability. Users and administrators should apply the Linux Kernel update containing the fix referenced in the vendor advisory (https://github.com/torvalds/linux/commit/8b519cbcabe836a441369fbec1a8a6518a709251) to remediate this issue.
Technical Details
- Classification
- {"confidence":0.95,"severitySource":"cvss-text","classifier":"rss-v2"}
- Article Source
- {"url":"http://www.zerodayinitiative.com/advisories/ZDI-26-575/","fetched":true,"fetchedAt":"2026-08-13T20:40:11.344Z","wordCount":199}
Threat ID: 6a7e2cf8bf8831d539c73bc1
Added to database: 08/13/2026, 20:45:44 UTC
Last enriched: 08/13/2026, 20:47:20 UTC
Last updated: 08/13/2026, 20:51:10 UTC
Views: 4
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