CVE-2026-52924 PoC Exploit Disclosed: 9.8 CVSS Linux Root Privilege Escalation

Security team NebuSec published technical details and functional exploit code for a critical Linux flaw. This Linux CVE-2026-52924 flaw triggers a use-after-free memory state within the kernel network stack. Upstream maintainers initially classified the bug as a denial-of-service issue. However, the published proof-of-concept shows that attackers can obtain full root privileges.

Why It Matters

This vulnerability introduces severe system security risks for enterprise servers. Attackers can escape standard user constraints and seize control of vulnerable hosts. Consequently, an unprivileged user can compromise server confidentiality and alter critical system files. In their public disclosure, researchers at NebuSec posted a video demonstration on X showing complete local root compromise. Furthermore, public exploit code increases the danger of rapid automation by threat actors. While security researchers confirmed the working exploit, telemetry shows no confirmed wild exploitation yet.

Today's exploit is for the latest Ubuntu 26.04, a 9-year-old OOB in SCTP: CVE-2026-52924.

It was introduced in Oct 2017 and fixed upstream in Jun 2026.

Discovered and exploited by the NebuSec security pipeline.

EXP source: https://t.co/3XVCKU1fPL pic.twitter.com/1KwTxvWPju

— Cyber Meowfia (@cybermeowfia) September 4, 2026

How the Attack Works

The flaw resides within the Stream Control Transmission Protocol handling routines. Specifically, the bug appears when the kernel processes a Stale Cookie error during connection setup. During this event, the kernel rolls an association back to a waiting state. Consequently, the stream update function frees the previous stream table without clearing cached pointers. Later, the protocol dequeue scheduler accesses this freed memory block. This sequence triggers a slab use-after-free condition. Security researchers at CyberMeowfia released a public proof-of-concept repository detailing this exact execution path.

Affected Versions

The upstream bug dates back to code introduced in October 2017. Therefore, the Linux CVE-2026-52924 vulnerability affects multiple long-term kernel branches. Testing verified the flaw on Ubuntu kernel version 7.0.0-28.

Patch and Mitigation Steps

Upstream developers resolved the issue by purging the association outqueue during stale cookie events. This update drops pending transmission state and clears scheduler pointers. Linux administrators should update system kernels immediately to protect against local privilege escalation. Alternatively, administrators can disable the protocol module if systems do not require SCTP services.

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Written by

@DdoS · Security Researcher

Do Son

Do Son is the Founder and Editor of SecurityOnline.info. Working in cybersecurity since 2013, he reports on vulnerabilities, malware, and emerging threats, providing timely analysis to help organizations and individuals stay ahead of evolving risks.