CVE-2026-67324 in GitPython
Summary
by MITRE • 08/01/2026
GitPython 3.1.50 fails to recognize joined short-option forms such as -u<value> (the short form of --upload-pack=<value>) when enforcing its default unsafe-option gate. When an application passes attacker-influenced clone options into Repo.clone_from(..., multi_options=..., allow_unsafe_options=False), an attacker can supply -u<helper> to bypass the gate that blocks --upload-pack/-u, causing Git to execute the specified helper command during clone. Fixed in 3.1.51.
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Analysis
by VulDB Data Team • 08/01/2026
The vulnerability in GitPython 3.1.50 represents a critical security flaw in how the library handles command-line option parsing for git operations, specifically affecting the Repo.clone_from method when using multi_options parameter with allow_unsafe_options set to False. This issue stems from an incomplete implementation of the unsafe options gate that was designed to prevent execution of potentially dangerous git commands through user-supplied parameters. The flaw occurs because the validation logic fails to properly recognize and block joined short-form options where the option and its value are concatenated without a space, such as -u<value> instead of -u <value>. This oversight creates a bypass mechanism that allows attackers to circumvent security controls intended to prevent execution of arbitrary helper commands.
The technical implementation of this vulnerability involves GitPython's parsing logic that processes command-line arguments for git operations. When allow_unsafe_options=False, the library should block dangerous options like --upload-pack and its short form -u to prevent command injection attacks through helper programs. However, the validation mechanism only checks for explicit option names without properly accounting for concatenated forms where the option and value are joined together. This parsing gap allows an attacker to provide -u<helper> as a parameter, which git interprets correctly despite being blocked by GitPython's safety mechanisms. The vulnerability demonstrates a classic input validation weakness where the system fails to normalize or fully parse command-line arguments before applying security controls.
From an operational impact perspective, this vulnerability enables attackers to execute arbitrary helper commands during git clone operations through specially crafted input parameters. An attacker could potentially leverage this to run malicious code on systems performing git clones with user-supplied parameters, especially in environments where GitPython is used for automated deployment processes or code repository management. The risk is particularly elevated in applications that accept untrusted input for git operations, as the bypass mechanism allows execution of helper programs that might be configured to perform unauthorized actions on the system. This could lead to privilege escalation, data exfiltration, or system compromise depending on the capabilities of the helper commands available in the target environment.
The vulnerability aligns with CWE-20, which describes improper input validation, and can be mapped to ATT&CK technique T1059.006 for command and script injection. It also reflects a broader category of security flaws related to argument parsing and command execution that frequently appear in software libraries handling system commands. Organizations using GitPython in applications that process user input should immediately update to version 3.1.51 or later, as this release includes the necessary fixes to properly handle joined short-form options in option validation. The mitigation strategy involves both immediate patching of the library and implementation of additional input sanitization measures for any application code that processes git parameters from untrusted sources, ensuring that all command-line arguments are properly validated regardless of their format or concatenation style.
This vulnerability highlights the importance of comprehensive testing for edge cases in security-sensitive parsing logic. The fix implemented in GitPython 3.1.51 addresses the specific gap by enhancing the option validation to recognize and block concatenated short-form options, ensuring that all forms of potentially dangerous parameters are properly handled. Security teams should monitor for similar patterns in other libraries that handle command-line argument parsing and ensure that input validation logic accounts for various parameter formats including joined options, quoted arguments, and alternative syntaxes that might bypass security controls. The incident serves as a reminder of the critical nature of thorough testing for security controls, particularly when dealing with system-level operations where malformed input could lead to arbitrary code execution.