CVE-2026-76233 in Renovate
Summary
by MITRE • 08/19/2026
Renovate versions from 39.53.0 before 40.33.0 contain a command injection vulnerability in the gleam manager where the depName parameter is appended to gleam deps update commands without proper sanitization. Attackers with repository write access can craft malicious gleam.toml files to execute arbitrary commands on the machine running Renovate.
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Analysis
by VulDB Data Team • 08/19/2026
The identified security flaw resides within the Gleam package manager integration of Renovate, specifically affecting versions ranging from 39.53.0 up to but not including 40.33.0. This vulnerability is classified as a command injection issue, which allows an attacker with repository write access to execute arbitrary operating system commands on the host machine where Renovate is running. The root cause lies in the improper sanitization of user-supplied input during the construction of shell commands. Specifically, when Renovate processes updates for Gleam dependencies, it constructs a command string by appending the depName parameter directly into gleam deps update instructions without adequate validation or escaping mechanisms to neutralize special characters that could alter command execution flow.
From a technical perspective, this flaw represents a classic instance of CWE-78 Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The vulnerability exploits the trust placed in configuration files managed by Renovate. By crafting a malicious gleam.toml file that contains specially crafted dependency names containing shell metacharacters such as semicolons, pipes, or backticks, an attacker can break out of the intended command context. For example, if the internal logic constructs a command like gleam deps update depName, and depName is set to malicious_input; rm -rf /, the resulting executed command becomes gleam deps update malicious_input; rm -rf /. This allows for arbitrary code execution with the privileges of the user account running the Renovate process.
The operational impact of this vulnerability is severe due to its potential for remote code execution within automated dependency management pipelines. Since Renovate often runs in continuous integration or deployment environments, successful exploitation could lead to full compromise of the underlying infrastructure. Attackers can leverage this access to exfiltrate sensitive data, install persistent backdoors, pivot to other systems on the network, or disrupt service availability by modifying system files. The requirement for repository write access means that threat actors typically need prior foothold within a project's source control history, such as through compromised credentials or social engineering attacks targeting maintainers, to inject these malicious configuration changes.
To mitigate this risk, organizations must upgrade Renovate to version 40.33.0 or later, where the issue has been resolved by implementing strict input validation and proper command argument separation rather than string concatenation for shell execution. In environments where immediate upgrading is not feasible, defensive measures should include restricting repository write permissions to trusted individuals only, enabling branch protection rules that require code review before merging changes to configuration files like gleam.toml, and isolating Renovate processes within restricted containers or sandboxed environments with minimal host privileges. Additionally, monitoring logs for unusual command executions originating from the Gleam manager can aid in early detection of exploitation attempts aligned with ATT&CK technique T1059 Command and Scripting Interpreter.