[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are two issues related to the mapping of pages belonging to other domains: For one, an assertion is wrong there, where the case actually needs handling. A NULL pointer de-reference could result on a release build. This is CVE-2025-58144. And then the P2M lock isn't held until a page reference was actually obtained (or the attempt to do so has failed). Otherwise the page can not only change type, but even ownership in between, thus allowing domain boundaries to be violated. This is CVE-2025-58145.
Use CWE-476, Xen vendor hub and Xen product page to widen CVE-2025-58144 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2025-58143, CVE-2025-58142 and CVE-2025-27466 for nearby disclosures in the same product family.