CVE detail
CVE-2026-23553
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 the guest kernel correctly isolating between tasks. Consider: 1) vCPU runs on CPU A, running task 1. 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB. 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB. 4) vCPU moves back to CPU A. Xen skips IBPB again. Now, task 2 is running on CPU A with task 1's training still in the BTB.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 13.9 · diversity 11.5 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
3 source links · newest first
- http://xenbits.xen.org/xsa/advisory-479.htmlxenbits.xen.org
No excerpt available.
Vendor Advisoryxenbits.xen.orgJan 28, 2026, 4:16 PM - http://www.openwall.com/lists/oss-security/2026/01/27/3www.openwall.com
No excerpt available.
Exploitwww.openwall.comJan 28, 2026, 4:16 PM - https://xenbits.xenproject.org/xsa/advisory-479.htmlxenbits.xenproject.org
No excerpt available.
Vendor Advisoryxenbits.xenproject.orgJan 28, 2026, 4:16 PM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
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