In the Linux kernel, a high-severity vulnerability has been identified that allows local attackers to exploit a buffer overflow when retrieving the PEK CSR. This vulnerability allows attackers to leak sensitive data to userspace, posing a significant risk to organizational security.
The vulnerability, assigned CVE-2026-31699, has a CVSS score of 7.1, indicating a high severity level. The attack vector is local, and the complexity is low, meaning that an attacker with low privileges can exploit this vulnerability without requiring user interaction.
Risk to organizations includes the potential for data leakage and unauthorized access to sensitive information. Organizations should prioritize patching immediately.
Currently, the vulnerability is awaiting analysis, and there are no known public exploits. However, with its high exploitability potential, organizations must take proactive measures to ensure their systems are secure.
Vulnerability Details
This vulnerability allows local attackers to exploit a buffer overflow when attempting to copy the CSR to userspace if the PSP command fails. If the failure is due to an invalid length, it can lead to copying more bytes than allowed, overflowing the kernel-allocated buffer.
The CVSS score of 7.1 indicates high severity, with high confidentiality impact and availability impact, while integrity impact remains unaffected. The vulnerability is classified under the Linux kernel's crypto subsystem.
The vulnerability was published on May 1, 2026, and is currently classified as awaiting analysis.
Technical Analysis
The root cause of this vulnerability lies in the handling of the PEK CSR in the Linux kernel. When the firmware command fails, and the length is invalid, the kernel attempts to copy an oversized buffer to userspace, leading to a buffer overflow.
The attack vector is local, meaning an attacker must have access to the system to exploit this vulnerability. The attack complexity is low, as it requires low privileges and does not need user interaction.
This vulnerability affects the confidentiality by potentially leaking sensitive information, while the availability impact implies that the system's availability may be compromised.
Risk & Impact Analysis
Organizations face significant risks due to this vulnerability, particularly regarding data leakage and unauthorized access to sensitive information. The potential for local exploitation means that attackers with low privileges could cause substantial harm.
The blast radius of this vulnerability could be extensive, as it affects the core functionality of the Linux kernel's crypto subsystem. Given the high CVSS score, organizations should address this vulnerability in their priority patch cycle.
Considering the EPSS score of 0.000120000 and its percentile ranking, the probability of exploitation remains low; however, the consequences of an exploit are severe. Therefore, urgency for remediation is warranted.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch are affected by this vulnerability. Organizations should consult their Linux kernel documentation for specific version details.
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the latest patches provided by the Linux kernel maintainers. Ensure that systems are updated to the latest stable version of the kernel to avoid exploitation.
In instances where immediate patching is not possible, organizations should implement configuration hardening techniques to limit access to the affected components and monitor for any suspicious activity.
For ongoing security validation, organizations may consider utilizing continuous penetration testing to identify similar weaknesses.
Detection Guidance
Organizations should monitor logs for unusual access patterns related to the crypto subsystem. Additionally, behavioral anomalies in user interactions with the system should be flagged for further investigation.
Implementing network signatures to detect attempts to trigger this vulnerability can also help in identifying potential exploitation attempts.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-31699 lies in its representation of ongoing vulnerabilities within the core components of operating systems. Security teams must remain vigilant and continuously assess their systems for such weaknesses.
This vulnerability highlights the importance of thorough testing during the development of kernel modules and drivers. Lessons learned from this incident can inform better security practices in future developments.
Organizations should consider reviewing their penetration testing methodology to ensure comprehensive coverage of such vulnerabilities in their security assessments.
Regular updates from threat intelligence sources, including vulnerability management programs, can help organizations stay ahead of emerging threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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