CVE-2026-84837 in RPM
Summary
by MITRE • 09/02/2026
A flaw was found in rpm. An attacker can exploit a command injection vulnerability by influencing the path or filename of a tarball processed by `rpmbuild -t*` to include shell metacharacters. This is particularly relevant in automated build or continuous integration (CI) workflows that ingest externally supplied artifact names. Successful exploitation allows for arbitrary command execution with the privileges of the build user, which could lead to information disclosure or disruption of the build environment.
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Analysis
by VulDB Data Team • 09/02/2026
The vulnerability identified within the RPM Package Manager represents a critical security flaw rooted in improper input validation and sanitization mechanisms during archive processing operations. Specifically, this issue affects commands such as rpmbuild -t*, where the tool is designed to create source or binary packages from tarballs. The core technical deficiency lies in how the application handles file paths and filenames provided by external sources. When an attacker can influence these inputs, they are able to inject shell metacharacters into the filename string before it is processed by underlying system commands. This lack of rigorous escaping allows for command injection, a classic vulnerability class where untrusted data is executed as part of a command line instruction without proper validation.
In automated build environments and continuous integration workflows, this flaw poses a significant risk because these systems frequently ingest artifacts from various sources to compile software packages. If the filename or path of an uploaded tarball contains specially crafted shell metacharacters, the rpmbuild utility may interpret them as executable commands rather than literal file name components. This behavior deviates from secure coding practices which dictate that all external inputs must be treated with suspicion and strictly validated against a whitelist of allowed characters or properly escaped before being passed to system shells. The absence of such safeguards creates an attack vector where the integrity of the build process is compromised by maliciously crafted input data.
The operational impact of this vulnerability is severe, as successful exploitation grants an attacker arbitrary command execution capabilities with the privileges of the user account running the rpmbuild process. In typical CI/CD pipelines, these accounts often possess elevated permissions necessary to access source repositories, compile code, and publish packages. Consequently, an attacker could leverage this privilege escalation to exfiltrate sensitive information such as private keys, credentials stored in environment variables, or proprietary source code. Furthermore, the attacker could disrupt the build environment by deleting critical files, installing backdoors, or causing denial of service conditions that halt development workflows and impact organizational productivity.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifier CWE-78, which describes Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. From a tactical perspective, this exploitation technique corresponds to the ATT&CK framework techniques related to command and script interpretation, allowing adversaries to execute arbitrary commands on compromised systems within the pipeline infrastructure. To mitigate this risk, it is imperative that organizations update their RPM packages to versions where the input sanitization logic has been hardened to reject or safely escape shell metacharacters in filenames. Additionally, developers should implement strict validation rules for artifact names and consider running build processes with minimized privileges to limit the potential blast radius of any successful exploitation attempt.