prefecthq prefect up to 3.6.18 repository.py shlex.split reference argument injection

Summaryinfo

A vulnerability labeled as critical has been found in prefecthq prefect up to 3.6.18. This vulnerability affects the function shlex.split of the file src/integrations/prefect-github/prefect_github/repository.py. Executing a manipulation of the argument reference can lead to argument injection. This vulnerability appears as CVE-2026-3515. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in prefecthq prefect up to 3.6.18 and classified as critical. This vulnerability affects the function shlex.split of the file src/integrations/prefect-github/prefect_github/repository.py. The manipulation of the argument reference with an unknown input leads to a argument injection vulnerability. The CWE definition for the vulnerability is CWE-88. The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A vulnerability in the `GitHubRepository` block of the `prefect-github` integration in Prefect version 3.6.18 allows an attacker to inject arbitrary git command-line options via the `reference` field. The `reference` field is concatenated directly into a `git clone` command string without proper sanitization, and then parsed by `shlex.split()`. This enables injection of options such as `-c`, leading to potential Server-Side Request Forgery (SSRF), credential theft, or remote code execution (RCE). The vulnerability affects both the `aget_directory()` and `get_directory()` methods in `src/integrations/prefect-github/prefect_github/repository.py`. This issue does not affect the GitLab and BitBucket integrations, which use a safer list-based command construction approach.

The advisory is shared for download at huntr.com. This vulnerability was named CVE-2026-3515 since 03/04/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/25/2026). The MITRE ATT&CK project declares the attack technique as T1059.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-31563). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• prefecthq

Name

• prefect

Version

• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5
• 3.6.6
• 3.6.7
• 3.6.8
• 3.6.9
• 3.6.10
• 3.6.11
• 3.6.12
• 3.6.13
• 3.6.14
• 3.6.15
• 3.6.16
• 3.6.17
• 3.6.18

CPE 2.3info

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CPE 2.2info

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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