Ubuntu has officially reached a significant milestone in its multi-year "oxidation" initiative, marking the complete replacement of the traditional GNU Core Utilities with the Rust-based uutils suite. With the release of Ubuntu 26.10, the final holdouts—the essential command-line tools cp, mv, and rm—have been successfully migrated to their Rust counterparts. This transition represents a major structural shift for the distribution, reflecting a broader industry trend toward memory-safe programming languages in foundational system software.
The GNU Core Utilities, which have served as the backbone of Unix-like operating systems for decades, were historically written in C. While performant and battle-tested, C-based codebases are inherently susceptible to memory safety vulnerabilities, such as buffer overflows and use-after-free errors. By adopting uutils, a project that provides a drop-in, memory-safe alternative to the GNU stack, Canonical aims to harden the Ubuntu ecosystem against an entire class of security threats.
A Chronology of the Oxidation Strategy
The journey to modernize Ubuntu’s core infrastructure began in earnest last year, driven by Canonical’s commitment to security and technological sustainability. The effort, colloquially termed "oxidization," has been a methodical, iterative process designed to minimize disruption for end-users and system administrators.
In 2025, Ubuntu 25.10 served as the inaugural release to ship uutils coreutils as the default standard. This release was also notable for the adoption of sudo-rs, a memory-safe rewrite of the ubiquitous sudo command, replacing a utility that had remained largely unchanged for over 30 years.
Following the initial rollout, Canonical encountered technical hurdles that slowed the pace of implementation. The release of Ubuntu 26.04 LTS, a version characterized by its long-term stability requirements, saw the deliberate exclusion of the Rust-based versions of cp, mv, and rm. Developers identified several "Time-of-check to time-of-use" (TOCTOU) concurrency issues within these specific utilities—flaws that could potentially be exploited to bypass security controls. To ensure the integrity of the LTS release, the team opted to retain the mature GNU versions of these three critical tools while continuing development on the Rust alternatives.
Between December 2025 and March 2026, Canonical commissioned two rounds of security audits conducted by the cybersecurity firm Zellic. These audits were highly targeted, focusing on the most sensitive components of the coreutils suite. The audit process proved rigorous, resulting in the identification of 113 distinct issues. Of these, 44 were deemed significant enough to warrant the assignment of Common Vulnerabilities and Exposures (CVE) identifiers. Canonical reports that the vast majority of these findings have since been remediated, clearing the path for the full integration seen in the 26.10 release cycle.
Addressing Technical Challenges and Implementation Hurdles
The transition was not without its final-stage complications. In July 2026, the uutils version of the cp command was temporarily rolled back in the software archive after it triggered instability in live image builds. The incident served as a stress test for Canonical’s development pipeline. Because the issue was flagged as "Critical," the fix was prioritized for upstream development, ensuring that the migration remained on track for the 26.10 launch.
This incident highlights the complexity of replacing foundational utilities that have been refined over decades of real-world use. The uutils project, by design, treats any functional deviation from the original GNU utilities as a bug. This "drop-in" philosophy is essential for maintaining compatibility with thousands of existing shell scripts, build systems, and administrative workflows that rely on the specific behavior of traditional GNU tools.
Implications for Users and System Administrators
For the average Ubuntu user, the shift is entirely transparent. When executing commands at the terminal, the user experience remains unchanged; the Rust utilities accept the same flags, arguments, and syntax as their GNU predecessors. However, for power users and enterprise environments that require the original behavior of the GNU stack, Canonical has provided an official "opt-out" path. The package coreutils-from-gnu is available in the official repositories, allowing administrators to revert to the traditional C-based binaries if specific application compatibility requires it.
The long-term implication of this change is a significant reduction in the attack surface of the operating system. By replacing high-risk C code with Rust, Canonical is proactively addressing potential memory corruption vulnerabilities before they can be exploited. This is particularly vital for server and cloud environments, where Ubuntu is the dominant operating system.
Broader Context: Memory Safety and Industry Trends
The shift toward Rust is not unique to Canonical. The Linux kernel itself has begun integrating Rust support, and major technology companies, including Microsoft and Google, have increasingly invested in memory-safe languages to rewrite critical system components.
Canonical’s strategy is supported by its financial commitment to the ecosystem. Earlier this year, the company became a Gold Sponsor of the Trifecta Tech Foundation, pledging €40,000 annually to support the development of memory-safe system software. This funding is currently being directed toward the development of ntpd-rs, a Rust-based implementation of the Network Time Protocol daemon. This project is currently in the testing phase and is expected to become the default in Ubuntu 27.04.
The "oxidization" of Ubuntu is characterized by a measured, risk-averse approach. Rather than forcing a wholesale transition that could jeopardize system stability, Canonical is systematically evaluating each component. The success of the coreutils migration provides a blueprint for future initiatives, proving that large-scale infrastructure overhauls can be achieved without compromising the core utility of the operating system.
The Road Ahead
With the core utilities fully transitioned, the focus for the development team will likely shift toward further hardening the user-space environment and refining the performance of these Rust-based replacements. While the immediate goal of replacing core system binaries is nearing completion, the underlying philosophy of memory safety is expected to guide the development of future Ubuntu releases for years to come.
As the distribution moves toward the next release cycle, the focus will likely turn to identifying other critical system services that could benefit from a similar rewrite. The collaborative nature of these projects—often involving close cooperation between distribution maintainers, the Rust community, and independent security auditors—demonstrates a maturing model for how open-source software can evolve to meet modern security requirements.
For the open-source community, Ubuntu’s progress serves as a significant proof-of-concept. It demonstrates that the transition to memory-safe languages, while technically demanding and fraught with potential for regression, is both achievable and necessary for the future of robust, secure computing. As Ubuntu continues to integrate these modern tools, it cements its position at the forefront of the movement to modernize the foundations of the Linux operating system.
