Meta FAIRChem Vulnerability Allows Remote Code Execution via Deserialization Flaw
A deserialization vulnerability in Meta FAIRChem's run_validation function enables remote code execution, with a CVSS score of 7.8.
A critical vulnerability has been identified in Meta FAIRChem, a platform developed by Meta's AI research division, that allows for remote code execution. The flaw, detailed in advisory ZDI-26-808 by the Zero Day Initiative, stems from an improper handling of serialized data within the run_validation function.
Specifically, the vulnerability lies in the way the FAIRChem software parses pickle files. Pickle is a Python module used for serializing and de-serializing Python object structures. When the software fails to adequately validate user-supplied data before deserializing it, an attacker can craft a malicious pickle file. When this file is processed by the run_validation function, it can lead to the deserialization of untrusted data, ultimately allowing an attacker to execute arbitrary code.
The exploitation of this vulnerability requires user interaction. An attacker would need to trick a user into visiting a malicious web page or opening a specially crafted file that contains the malicious pickle data. Once the user interacts with the malicious content, the FAIRChem application on the target system could be compromised.
The severity of this vulnerability is underscored by its CVSS score of 7.8, classifying it as high. Successful exploitation could grant an attacker the ability to execute code within the context of the current process, potentially leading to unauthorized access, data theft, or further system compromise.
Meta has acknowledged the vulnerability and has released an update to address the issue. The fix is available through a pull request on the FAIRChem GitHub repository, specifically at https://github.com/facebookresearch/fairchem/pull/1935. Users of Meta FAIRChem are strongly advised to apply this update as soon as possible to mitigate the risk.
The vulnerability was initially reported to Meta on March 4, 2026, and the Zero Day Initiative coordinated a public release of the advisory on October 26, 2026. The advisory was updated on the same day. The vulnerability was reported by an anonymous researcher.
This discovery highlights the ongoing risks associated with deserialization vulnerabilities, which remain a common attack vector across various software platforms. Developers must prioritize robust input validation and secure deserialization practices to prevent such critical security flaws from being exploited.
The Zero Day Initiative advisory ZDI-26-801 provides further technical details on the Meta FAIRChem deserialization vulnerability. It specifies that the flaw lies within the parsing of pickle files, stemming from insufficient validation of user-supplied data, which can lead to the deserialization of untrusted data. The advisory also notes that user interaction, such as visiting a malicious page or opening a malicious file, is required for exploitation.
This advisory provides further technical details on the Meta FAIRChem deserialization vulnerability, specifically identifying the flaw within the parsing of pickle files. It also clarifies that user interaction, such as visiting a malicious page or opening a malicious file, is required for exploitation. The vulnerability has been assigned a CVSS score of 7.8 and was reported by Mat Powell of TrendAI Zero Day Initiative.
This advisory from Zero Day Initiative, ZDI-26-803, provides further technical details on the deserialization vulnerability affecting Meta FAIRChem's AdsorbMLRunner. It confirms that user interaction is required, typically by visiting a malicious webpage or opening a crafted file, to trigger the remote code execution. The vulnerability stems from improper validation of user-supplied data during the parsing of pickle files, allowing attackers to execute code within the context of the current process.
This advisory from Zero Day Initiative provides specific technical details on the Meta FAIRChem deserialization vulnerability, identified as ZDI-26-799. It confirms that the flaw lies within the parsing of pickle files, stemming from inadequate validation of user-supplied data, which can lead to deserialization of untrusted data and subsequent remote code execution in the context of the current process. The vulnerability requires user interaction, such as visiting a malicious page or opening a malicious file, and has a CVSS score of 7.8.
The Zero Day Initiative advisory ZDI-26-806 details a deserialization of untrusted data vulnerability affecting Meta FAIRChem. This advisory provides specific technical details on how remote attackers can execute arbitrary code by tricking a user into visiting a malicious page or opening a malicious file, leveraging the flaw within the parsing of pickle files. The vulnerability has a CVSS rating of 7.8 and has been patched by Meta.
The Zero Day Initiative advisory ZDI-26-805 provides further technical details on the Meta FAIRChem deserialization vulnerability. It confirms the flaw exists within the parsing of pickle files, stemming from inadequate validation of user-supplied data, which can lead to the deserialization of untrusted data. The advisory also notes that the vulnerability requires user interaction, such as visiting a malicious webpage or opening a crafted file, to be exploited for remote code execution.
The Zero Day Initiative advisory ZDI-26-802 provides further technical details on the Meta FAIRChem deserialization vulnerability, specifying that the flaw lies within the parsing of pickle files. This vulnerability requires user interaction, such as visiting a malicious page or opening a crafted file, to be exploited and allows for arbitrary code execution in the context of the current process. Meta has released a patch for this issue, with the fix available via a pull request on their GitHub repository.
This advisory provides further technical details on the Meta FAIRChem vulnerability, specifically identifying the flaw within the parsing of pickle files. It highlights that the issue stems from improper validation of user-supplied data, leading to deserialization of untrusted data. The vulnerability, tracked as ZDI-26-796, has a CVSS score of 7.8 and requires user interaction, such as visiting a malicious page or opening a crafted file, for exploitation.
This advisory from Zero Day Initiative (ZDI-26-794) provides further technical details on the Meta FAIRChem ion_db_path deserialization vulnerability. It confirms that user interaction is required, typically by tricking a user into visiting a malicious page or opening a crafted file. The vulnerability stems from improper validation of user-supplied data during pickle file parsing, allowing for remote code execution within the context of the current process.
The Zero Day Initiative advisory ZDI-26-795 provides further technical details on this deserialization vulnerability affecting Meta FAIRChem. It specifies that the flaw exists within the parsing of pickle files, stemming from inadequate validation of user-supplied data. The advisory also notes that user interaction is required, typically by visiting a malicious page or opening a crafted file, to trigger remote code execution in the context of the current process. A patch has been issued by Meta, with the disclosure timeline indicating coordinated public release on October 26, 2026.
The Zero Day Initiative advisory ZDI-26-793 provides further technical details on the Meta FAIRChem deserialization vulnerability. It specifies that the flaw exists within the parsing of pickle files and requires user interaction, such as visiting a malicious page or opening a malicious file, for exploitation. The vulnerability has been assigned a CVSS score of 7.8, indicating a high severity.
This advisory provides the specific CVE identifier ZDI-26-800 for the previously reported Meta FAIRChem deserialization vulnerability. It also details that the vulnerability requires user interaction, such as visiting a malicious webpage or opening a crafted file, for exploitation. The CVSS score remains 7.8, and a fix has been released by Meta.
This advisory, ZDI-26-809, specifically details a deserialization vulnerability within Meta FAIRChem's dense_eval dft-targets component. While the existing story mentions a vulnerability in the run_validation function, this new information pinpoints a different, though related, component that is susceptible to remote code execution. The CVSS score remains consistent at 7.8, and user interaction is still required for exploitation.
This advisory specifically details a deserialization vulnerability within the get_computational_df_to_predict function of Meta FAIRChem, which differs from the run_validation function mentioned in the previous report. The vulnerability, identified as ZDI-26-807, allows for remote code execution through the parsing of untrusted pickle files and has a CVSS score of 7.8. A fix has been released via a GitHub pull request.
The Zero Day Initiative advisory ZDI-26-804 provides further technical details on the Meta FAIRChem bulk class deserialization vulnerability. It clarifies that the flaw exists within the parsing of pickle files, stemming from inadequate validation of user-supplied data, which can lead to the deserialization of untrusted data. The advisory also notes that exploitation requires user interaction, such as visiting a malicious page or opening a malicious file, and attributes the discovery to Mat Powell of TrendAI Zero Day Initiative.
This advisory updates the initial disclosure with a coordinated public release date of October 26, 2026, and includes a specific CVE identifier for the vulnerability. The vulnerability, reported by Mat Powell of TrendAI Zero Day Initiative, was initially disclosed to the vendor on March 26, 2026.