from lxml import etree as E

class DenyExternal(E.Resolver):
    def resolve(self, url, public_id, context):
        raise ValueError("External resources are disabled")

def parse(text):
    if "<!DOCTYPE" in text.upper() or "<!ENTITY" in text.upper():
        raise ValueError("Declarations are disabled for untrusted XML")
    parser = E.XMLParser(resolve_entities=False, load_dtd=False,
                         no_network=True, huge_tree=False)
    parser.resolvers.add(DenyExternal())
    return E.fromstring(text.encode("utf-8"), parser)

source = "<rss version=\"2.0\"><channel><title>Seed circle updates</title><link>https://example.test/seeds</link><description>Local exchange notices</description><item><title>Marigold packets returned</title><link>https://example.test/seeds/p1</link><guid isPermaLink=\"false\">seed-update-001</guid></item></channel></rss>"
root = parse(source)
print(root.xpath("string(channel/title)"))
print(root.xpath("string(channel/item/guid)"))