Language: Go
Label: vulnerable
CWE: CWE-125 \u2014 Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.

Code:
func (p *Parser) isPrefixHeading(data []byte) bool {
	if data[0] != '#' {
		return false
	}

	if p.extensions&SpaceHeadings != 0 {
		level := skipCharN(data, 0, '#', 6)
		if level == len(data) || data[level] != ' ' {
			return false
		}
	}
	return true
}