"><img Src =q Onerror=prompt(8)> May 2026
The following example illustrates the vulnerability:
<img src="q" onError="prompt(8)"> In this example, the image tag attempts to load an image from a non-existent URL "q". Since the image fails to load, the JavaScript code in the "onError" attribute is executed, displaying a prompt box with the message "8". "><img src =q onError=prompt(8)>
The vulnerability arises when an image tag is crafted with an "onError" attribute that contains malicious JavaScript code. Specifically, when the image fails to load, the JavaScript code in the "onError" attribute is executed. This can be achieved by setting the "src" attribute of the image tag to a non-existent or invalid URL, triggering the "onError" event. img src="q" onError="prompt(8)">