Buffer Overflow Vulnerability in Linux Kernel - CVE-2026-90327
Summary
DEBIAN-CVE-2026-90327: In the Linux kernel, the following vulnerability has been resolved: phonet: pep: do not write beyond optlen in getsockopt pep_getsockopt() clamps the reported length to the caller's buffer with min_t(), but then stores t... Affects linux versions 6.1.106-1 – 7.2~rc7-1~exp1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core component of the Linux operating system, responsible for managing hardware resources and providing essential services to applications. It supports a wide range of functionalities, including process management, memory management, and device control. The kernel is critical for system stability and security, making it essential to address any vulnerabilities that may arise.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the phonet subsystem related to the getsockopt function. Specifically, the pep_getsockopt function improperly handles the length of data being written to user space. While it clamps the reported length to the caller's buffer using min_t(), it subsequently writes a fixed size of sizeof(int) bytes using put_user. This can lead to a buffer overflow if the optlen provided by the user is smaller than sizeof(int), resulting in one to three bytes being written beyond the allocated buffer. This vulnerability can potentially allow an attacker to exploit the overflow, leading to undefined behavior or system crashes.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, users can avoid using the phonet subsystem or limit the use of getsockopt calls with optlen smaller than sizeof(int) until the package is updated.
Conclusion
CVE-2026-90327 is a critical vulnerability in the Linux kernel that can lead to buffer overflow issues. It is essential for users to update their systems to the patched version to mitigate potential risks. Utilizing tools like Vulert can help monitor for such vulnerabilities in real-time.
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FAQ
CVE-2026-90327 is a vulnerability in the Linux kernel that can lead to buffer overflow due to improper handling of data lengths in the getsockopt function.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected by this vulnerability.
The vulnerability can lead to undefined behavior, system crashes, or exploitation by attackers, which may compromise system security.
Yes, a patch has been released for the Linux kernel to address CVE-2026-90327. Users should update their Linux package to the latest version.
If immediate updates are not possible, consider avoiding the use of the phonet subsystem or limiting the use of getsockopt calls with small optlen values as a temporary workaround.
References
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