Vulnerability · medium · CVSS 5.6
Xen Security Advisory 525: Transient Scheduler Attacks update
Tier C · Keep an eye on it – Check if you’re affected
Who’s exposed: x86 systems running the Xen hypervisor
Tier C because: Hits tech teams
Reach
Attack
Damage
Fix
The Brief
- Xen Security Advisory 525 was updated on 2026-11-10 with new details on x86 Transient Scheduler Attacks.
- AMD reported further properties of Transient Scheduler Attacks, per the advisory's issue description.
- The advisory covers CVE-2024-36350, CVE-2024-36357 and CVE-2026-0004.
Why it matters
Developers running Xen hypervisors on x86 hardware should review the updated advisory to determine whether their systems are affected.
The checklist behind the tier
Checklist · 1 of 10 yes
| Yes | Hits tech teams | Xen is a hypervisor that servers and cloud platforms run, so ops teams are responsible for it. |
| No | Core infrastructure | Xen is a major hypervisor but a single product, not software nearly every team runs. |
| No | Popular tool | Xen is widely deployed in virtualization, but it is not mainstream developer tooling used by many teams directly. |
| No | Exploited in the wild | Open Source Security advisory describes new research properties; no source reports observed attacks. |
| No | Public exploit | Open Source Security advisory only describes the issue; no source mentions published exploit code. |
| No | Remote, no login | Open Source Security advisory does not state that network access without credentials is enough. |
| No | Full takeover | Open Source Security advisory does not describe code execution, root access or account takeover. |
| No | Secrets exposed | Open Source Security advisory describes transient-execution properties only; no source reports data stolen. |
| No | Supply chain | Open Source Security advisory covers a CPU scheduling flaw; no source reports compromised packages or updates. |
| No | No fix yet | Open Source Security advisory is an update to a Xen advisory; sources do not say no fix exists. |
The official record
From CVE.org, CISA’s Known Exploited Vulnerabilities catalog, FIRST EPSS and the GitHub Advisory Database. Where these answer a checklist fact, they win over the reporting.
CVE-2024-36350 ↗CVSS 5.6 medium AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
A transient execution vulnerability in some AMD processors may allow an attacker to infer data from previous stores, potentially resulting in the leakage of privileged information.
- Exploited
- Not in CISA’s exploited catalog
- EPSS
- <1% chance of exploitation in the next 30 days · higher than 43% of all CVEs
- Weakness
- CWE-1421
CVE-2024-36357 ↗CVSS 5.6 medium AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
A transient execution vulnerability in some AMD processors may allow an attacker to infer data in the L1D cache, potentially resulting in the leakage of sensitive information across privileged boundaries.
- Exploited
- Not in CISA’s exploited catalog
- EPSS
- <1% chance of exploitation in the next 30 days · higher than 30% of all CVEs
- Weakness
- CWE-1421
- Exploited
- Not in CISA’s exploited catalog
Timeline
Xen security team posted updated Xen Security Advisory 525
Open Source Security
Xen Security Advisory 525 v1 (CVE-2024-36350,CVE-2024-36357,CVE-2026-0004) - x86: Transient Scheduler Attacks (update)
Source
Xen Security Advisory 525 v1 (CVE-2024-36350,CVE-2024-36357,CVE-2026-0004) - x86: Transient Scheduler Attacks (update) ↗ Open Source Security · 54 min ago
First seen · 1 source · Full story page · How tiers are decided