CVE ID : CVE-2026-23553<\/p>\n
Published : Jan. 28, 2026, 4:16 p.m. | 51\u00a0minutes ago<\/p>\n
Description : In the context switch logic Xen attempts to skip an IBPB in the case of
\na vCPU returning to a CPU on which it was the previous vCPU to run.
\nWhile safe for Xen’s isolation between vCPUs, this prevents the guest
\nkernel correctly isolating between tasks. Consider:<\/p>\n
1) vCPU runs on CPU A, running task 1.
\n 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB.
\n 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB.
\n 4) vCPU moves back to CPU A. Xen skips IBPB again.<\/p>\n
Now, task 2 is running on CPU A with task 1’s training still in the BTB.<\/p>\n
Severity: 0.0 | NA<\/p>\n
Visit the link for more details, such as CVSS details, affected products, timeline, and more…\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"
CVE ID : CVE-2026-23553 Published : Jan. 28, 2026, 4:16 p.m. | 51\u00a0minutes ago Description : 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 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-75861","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/75861","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=75861"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/75861\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=75861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=75861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=75861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}