Use-After-Free Vulnerability in Linux Kernel's SMB Service
CVE-2025-37899

Currently unrated

Key Information:

Vendor

Linux

Status
Vendor
CVE Published:
20 May 2025

Badges

🥇 Trended No. 1📈 Trended📈 Score: 8,090💰 Ransomware👾 Exploit Exists🟡 Public PoC📰 News Worthy

What is CVE-2025-37899?

CVE-2025-37899 is a use-after-free vulnerability located in the SMB service of the Linux kernel, a fundamental component of many operating systems that utilize this open-source kernel. The vulnerability arises in the session management process when the sess->user object can remain accessible even after it has been freed. This occurs if another thread sends a session setup request while the session is in the process of being released, leading to potential unpredictable behavior and system instability.

Such vulnerabilities can allow malicious actors to exploit the system, gain unauthorized access, or cause a denial of service. Given the widespread use of Linux in servers and cloud infrastructure, this flaw could significantly disrupt operations for organizations relying on Linux-based systems for critical applications and services.

Potential impact of CVE-2025-37899

  1. Unauthorized Access: Exploiting this vulnerability could enable attackers to manipulate session handling processes, potentially allowing them to execute unauthorized operations on behalf of legitimate users.

  2. Denial of Service: The instability caused by this vulnerability may lead to crashes or unresponsive services, affecting the availability of systems and applications critical to business operations.

  3. Data Integrity Risks: The unpredictability associated with a use-after-free flaw can result in data corruption or loss during active sessions, threatening the integrity and reliability of stored data within affected systems.

Affected Version(s)

Linux 0626e6641f6b467447c81dd7678a69c66f7746cf

Linux 0626e6641f6b467447c81dd7678a69c66f7746cf < 02d16046cd11a5c037b28c12ffb818c56dd3ef43

Linux 0626e6641f6b467447c81dd7678a69c66f7746cf < 2fc9feff45d92a92cd5f96487655d5be23fb7e2b

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

News Articles

How OpenAI’s o3 model uncovered a zero-day vulnerability in the Linux kernel

Technology expert Sean Heelan explained how he discovered a zero-day vulnerability in Linux using OpenAI&#39;s AI model &#39; o3 &#39;, which dramatically improves its ability to reason about code. How I used o3 to find CVE-2025-37899, a remote zeroday vulnerability in the Linux kernel&#39;s SMB im...

2 days ago

It’s A Trap! – PSW #876

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5 days ago

Linux Zero-Day Vulnerability Discovered Using Frontier AI

Large language models have taken a big step forward in their ability to help chase down code flaws, said vulnerability researcher who successfully trained OpenAI's

2 weeks ago

References

Timeline

  • 💰

    Used in Ransomware

  • 🥇

    Vulnerability reached the number 1 worldwide trending spot

  • 📈

    Vulnerability started trending

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • 📰

    First article discovered by CybersecurityNews

  • Vulnerability published

  • Vulnerability Reserved

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CVE-2025-37899 : Use-After-Free Vulnerability in Linux Kernel's SMB Service