CVE-2026-31890 in inspektor-gadget
Summary
by MITRE • 03/12/2026
Inspektor Gadget is a set of tools and framework for data collection and system inspection on Kubernetes clusters and Linux hosts using eBPF. Prior to 0.50.1, in a situation where the ring-buffer of a gadget is – incidentally or maliciously – already full, the gadget will silently drop events. The include/gadget/buffer.h file contains definitions for the Buffer API that gadgets can use to, among the other things, transfer data from eBPF programs to userspace. For hosts running a modern enough Linux kernel (>= 5.8), this transfer mechanism is based on ring-buffers. The size of the ring-buffer for the gadgets is hard-coded to 256KB. When a gadget_reserve_buf fails because of insufficient space, the gadget silently cleans up without producing an alert. The lost count reported by the eBPF operator, when using ring-buffers – the modern choice – is hardcoded to zero. The vulnerability can be used by a malicious event source (e.g. a compromised container) to cause a Denial Of Service, forcing the system to drop events coming from other containers (or the same container). This vulnerability is fixed in 0.50.1.
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Analysis
by VulDB Data Team • 03/20/2026
The vulnerability described in CVE-2026-31890 affects Inspektor Gadget, a comprehensive set of tools and frameworks designed for data collection and system inspection within Kubernetes clusters and Linux host environments utilizing eBPF technology. This security flaw exists in versions prior to 0.50.1 and represents a critical design oversight in the buffer management system that governs data transfer between eBPF programs and userspace components. The affected system relies on ring-buffer mechanisms for efficient data transmission, specifically implemented in the include/gadget/buffer.h file which contains the core Buffer API definitions that gadgets utilize for inter-process communication.
The technical implementation of this vulnerability stems from the hard-coded ring-buffer size of 256KB that is configured for all gadgets operating on Linux kernels version 5.8 and above. When the gadget_reserve_buf function encounters insufficient space within this predetermined buffer capacity, the system exhibits silent failure behavior rather than implementing proper error handling or alert mechanisms. This design choice creates a scenario where event loss occurs without any notification or logging, making it extremely difficult to detect when the system is experiencing data drop issues. The eBPF operator's lost count reporting mechanism is also hardcoded to zero, effectively masking the actual event loss that has occurred within the system.
The operational impact of this vulnerability extends beyond simple data loss, creating potential for significant service disruption and security implications. A malicious event source such as a compromised container can exploit this weakness to deliberately force the system into dropping events from other containers or even from the same compromised container, effectively creating a denial of service condition. This behavior allows attackers to systematically disrupt monitoring capabilities and potentially hide malicious activities within the system. The silent nature of the event dropping means that administrators remain unaware of the compromised state until more severe consequences manifest, making this vulnerability particularly dangerous in production environments where continuous monitoring is essential.
The vulnerability aligns with CWE-704 in the Common Weakness Enumeration system, which addresses improper handling of resource exhaustion conditions, and represents a specific instance of CWE-399 related to resource management errors. From an ATT&CK framework perspective, this vulnerability maps to T1489 Denial of Service through resource exhaustion and potentially T1566 Privilege Escalation through the exploitation of system monitoring capabilities. The remediation approach requires updating to Inspektor Gadget version 0.50.1 where the buffer management system has been properly enhanced to handle overflow conditions with appropriate error reporting and notification mechanisms. Organizations should also implement monitoring for buffer utilization patterns and establish alerting systems to detect when buffer capacity approaches critical thresholds, ensuring that administrators can proactively address potential issues before they escalate into denial of service conditions.