How severe is CVE-2018-15468?

CVE-2018-15468 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-15468 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-15468?

CVE-2018-15468 affects Xen. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-15468?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-15468 published?

CVE-2018-15468 was published on 2018-08-17 and last updated on 2026-06-17.

CVE-2018-15468

CVE-2018-15468 is a medium-severity vulnerability in Xen with a CVSS 3.x base score of 6.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.0)
CVSS v2: 4.9
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Xen
Published: 2018-08-17
Last modified: 2026-06-17

Description

An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service.

Frequently asked questions

What is CVE-2018-15468?: An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service.
How severe is CVE-2018-15468?: CVE-2018-15468 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-15468 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-15468?: CVE-2018-15468 affects Xen. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-15468?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-15468 published?: CVE-2018-15468 was published on 2018-08-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*

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