CVE-2026-29190 in karapace
Summary
by MITRE • 03/07/2026
Karapace is an open-source implementation of Kafka REST and Schema Registry. Prior to version 6.0.0, there is a Path Traversal vulnerability in the backup reader (backup/backends/v3/backend.py). If a malicious backup file is provided to Karapace, an attacker may exploit insufficient path validation to perform arbitrary file read on the system where Karapace is running. The issue affects deployments that use the backup/restore functionality and process backups from untrusted sources. The impact depends on the file system permissions of the Karapace process. This issue has been patched in version 6.0.0.
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Analysis
by VulDB Data Team • 03/12/2026
The vulnerability identified as CVE-2026-29190 affects Karapace, an open-source implementation that provides Kafka REST and Schema Registry functionality. This system serves as a critical component in distributed streaming architectures, enabling applications to interact with Apache Kafka through RESTful APIs. The flaw exists within the backup reader functionality specifically in the file backup/backends/v3/backend.py, which handles the processing of backup files for restoration purposes. Organizations that rely on Karapace's backup and restore capabilities for maintaining their Kafka cluster configurations and schema definitions are particularly at risk when dealing with untrusted backup sources.
The technical root cause of this vulnerability stems from inadequate path validation mechanisms within the backup processing module. When Karapace processes backup files, it fails to properly sanitize or validate file paths that may be included in these archives. This insufficient validation creates an opportunity for attackers to craft malicious backup files containing specially formatted paths that can traverse the file system beyond intended boundaries. The vulnerability operates as a path traversal attack where attacker-controlled input is not properly validated against the system's file system structure, allowing arbitrary file read operations to occur. This flaw aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal vulnerabilities.
The operational impact of this vulnerability extends significantly based on the file system permissions assigned to the Karapace process. When an attacker successfully exploits this vulnerability, they can potentially read any file accessible to the Karapace service account, which could include sensitive configuration files, authentication credentials, schema definitions, or other critical system data. The severity of the impact directly correlates with the privilege level of the Karapace process, as a process running with elevated permissions could expose confidential information across the entire system. This vulnerability particularly affects deployments where backup files are processed from untrusted sources, such as third-party vendors, automated backup systems, or any scenario where the integrity of backup archives cannot be guaranteed. Organizations using Karapace in production environments with backup/restore functionality are at risk if they process backups from external sources without proper validation.
Mitigation strategies for this vulnerability begin with immediate upgrade to Karapace version 6.0.0 or later, which includes the necessary patches to address the path traversal issue. Beyond the immediate upgrade, organizations should implement comprehensive backup validation procedures that verify the integrity and contents of backup files before processing them through Karapace. This includes establishing strict access controls for the Karapace service account, ensuring it operates with the minimum required privileges to reduce potential damage from exploitation. Additionally, organizations should consider implementing network segmentation to limit access to Karapace backup functionality and establish monitoring protocols to detect anomalous file access patterns. The remediation approach should also include regular security assessments of backup processing workflows and ensuring that all backup sources are properly authenticated and validated before being processed by the system. This vulnerability demonstrates the critical importance of input validation in systems handling data import operations and underscores the need for security practices that follow the principle of least privilege and defense in depth as outlined in various cybersecurity frameworks and standards.