djehuty: Authenticated SPARQL injection in session editing allows writing arbitrary RDF triples

djehuty is a research data repository system developed by 4TU.ResearchData. Prior to version 26.3.2, an authenticated depositor can inject arbitrary SPARQL into a state-modifying (DELETE/INSERT) query by supplying a crafted session name, letting them write (and delete) arbitrary triples anywhere in the RDF store. Because the RDF store is shared across all accounts and datasets, this is an integrity compromise of the whole repository's metadata, not just the attacker's own records. Having a logged-in account is a precondition. djehuty allows self-registration via ORCID/SAML, so this is a low barrier in typical deployments. This issue has been patched in version 26.3.2.