Vulnerability in Xen

[ Description ]Official description

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] A common access pattern is a batch of Grant Copy operations acting on adjacent address ranges in the same source or destination page. For performance reasons, Xen caches details internally to reuse already validated data. The conditions on when to re-validate the internal data were not correct in some cases: - Frame numbers and grant references could wrongly be mixed up. This is CVE-2026-102703. - Copying by frame number (rather than grant reference) is permitted only when operating on the caller's own memory. The check to enforce this restriction was misplaced. This is CVE-2026-102704.

[ Fixes ]Fixes and patches

• Security bulletin: Xen xsa/advisory-523Vendor patch or bulletin · CERT-FR · xenbits.xen.org/xsa/advisory-523.html, cited by CERT-FR CERTFR-2026-AVI-1447

[ Advisories ]Government CERT advisories

• BSI CERT-Bund3 Nov 2026WID-SEC-2026-4308

  Xen: Multiple vulnerabilities allow bypassing security measures Translated from German

  Risk highCVE-2026-102704CVE-2026-102703
• CERT-FR3 Nov 2026CERTFR-2026-AVI-1447

  Multiple vulnerabilities in Xen Translated from French

  Multiple vulnerabilities have been discovered in Xen. They allow an attacker to cause a breach of data confidentiality and a breach of data integrity.

  CVE-2026-102704CVE-2026-102703

[ References ]References

• xenbits.xenproject.org/xsa/advisory-523.html