CVE-2023-50252 php-svg-lib unsafe attributes merge when parsing `use` tag

php-svg-lib is an SVG file parsing / rendering library. Prior to version 0.5.1, when handling <use> tag that references an <image> tag, it merges the attributes from the <use> tag to the <image> tag. The problem pops up especially when the href attribute from the <use> tag has not been sanitized. This can lead to an unsafe file read that can cause PHAR Deserialization vulnerability in PHP prior to version 8. Version 0.5.1 contains a patch for this issue.