KnpLabs snappy up to 1.7.0 on POSIX Configuration /usr/bin/wkhtmltopdf is_executable command os command injection

Summaryinfo

A vulnerability categorized as critical has been discovered in KnpLabs snappy up to 1.7.0 on POSIX. This vulnerability affects the function is_executable of the file /usr/bin/wkhtmltopdf of the component Configuration Handler. Executing a manipulation of the argument command can lead to os command injection. This vulnerability is tracked as CVE-2026-46643. The attack is restricted to local execution. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in KnpLabs snappy up to 1.7.0 on POSIX. This vulnerability affects the function is_executable of the file /usr/bin/wkhtmltopdf of the component Configuration Handler. The manipulation of the argument command with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.7.1, on POSIX, escapeshellarg(‘/usr/bin/wkhtmltopdf’) returns the literal string ‘/usr/bin/wkhtmltopdf’ with the single-quote characters included. is_executable() then looks for a file whose actual name contains those quote characters, which essentially never exists. The safe branch is dead code and $command always falls through to the raw, unescaped value. The rest of the arguments (options, input, output) are escaped correctly, so injection has to land in the binary string itself. That happens whenever the binary path is sourced from configuration that is user-influenced, derived from environment variables that ultimately come from request data, or concatenated with any user-controlled fragment. This issue has been patched in version 1.7.1.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-46643 since 05/15/2026. The exploitation appears to be easy. The attack needs to be approached locally. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1202.

Upgrading to version 1.7.1 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-36111). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• KnpLabs

Name

• snappy

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7.0

Website

• Product: https://github.com/KnpLabs/snappy/

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Once again VulDB remains the best source for vulnerability data.

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