How severe is CVE-2026-23554?

CVE-2026-23554 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-23554 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23554?

CVE-2026-23554 affects Xen. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23554?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-23554 have an EU (EUVD) identifier?

Yes. CVE-2026-23554 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14382.

When was CVE-2026-23554 published?

CVE-2026-23554 was published on 2026-03-23 and last updated on 2026-06-17.

CVE-2026-23554

CVE-2026-23554 is a high-severity vulnerability in Xen with a CVSS 3.x base score of 7.8. 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-367.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14382
Weakness: CWE-367
Affected product: Xen
Published: 2026-03-23
Last modified: 2026-06-17

Description

The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is dropped, so that multiple modifications done under the same locked region only issue a single flush. Freeing of paging structures however is not deferred until the flushing is done, and can result in freed pages transiently being present in cached state. Such stale entries can point to memory ranges not owned by the guest, thus allowing access to unintended memory regions.

Frequently asked questions

What is CVE-2026-23554?: The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is dropped, so that multiple modifications done under the same locked region only issue a single flush. Freeing of paging structures however is not deferred until the flushing is done, and can result in freed pages transiently being present in cached state. Such stale entries can point to memory ranges not owned by the guest, thus allowing access to unintended memory regions.
How severe is CVE-2026-23554?: CVE-2026-23554 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-23554 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23554?: CVE-2026-23554 affects Xen. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23554?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23554 have an EU (EUVD) identifier?: Yes. CVE-2026-23554 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14382.
When was CVE-2026-23554 published?: CVE-2026-23554 was published on 2026-03-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*

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