{"action":"Upgrade xen to 4.20.2+37-g61ff35323e-0+deb13u1 or later.","affected":[{"fixed":"4.20.2+37-g61ff35323e-0+deb13u1","introduced":"0"}],"component":"xen","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:13","exploited":false,"fixed_versions":["4.20.2+37-g61ff35323e-0+deb13u1"],"id":"tcs_01M5NR3WP2QB1SESSJEY3M08M8","modified_at":"2026-10-04T22:00:08.021895089Z","published_at":"2026-01-28T16:16:16.853Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2026-23553","https://security-tracker.debian.org/tracker/CVE-2026-23553"],"severity":{"label":"low","score":2.9},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2026-23553#Debian:13/xen","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2026-23553"}],"summary":"In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents"}