Cyber Resilience

CVE-2025-27465

Xen ≥ 4.9.0

Published
16 July 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0057 44th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2025-27465 is a medium-severity Improper Handling of Exceptional Conditions (CWE-755) vulnerability in Xen Xen. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-24 (Fail in Known State) and SI-17 (Fail-safe Procedures) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

Certain instructions need intercepting and emulating by Xen. In some cases Xen emulates the instruction by replaying it, using an executable stub. Some instructions may raise an exception, which is supposed to be handled gracefully. Certain replayed instructions have additional…

more

logic to set up and recover the changes to the arithmetic flags. For replayed instructions where the flags recovery logic is used, the metadata for exception handling was incorrect, preventing Xen from handling the the exception gracefully, treating it as fatal instead.

CWE(s)
CWE-755

Related Threats

MITRE ATT&CK Enterprise Techniques

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-34323Same product: Xen Xen
CVE-2025-58144Same product: Xen Xen
CVE-2026-23557Same product: Xen Xen
CVE-2026-23555Same product: Xen Xen
CVE-2023-34326Same product: Xen Xen
CVE-2024-45818Same product: Xen Xen
CVE-2025-58149Same product: Xen Xen
CVE-2024-31145Same product: Xen Xen
CVE-2024-31146Same product: Xen Xen
CVE-2023-46837Same product: Xen Xen

Affected Assets

xen
xen
≥ 4.9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SC-24 Fail in Known State good match

Requires the system to fail to a known safe state on specified failures, limiting the impact of unhandled exceptional conditions.

SI-17 Fail-safe Procedures good match

Mandates explicit fail-safe procedures triggered by indicated failures, structurally preventing unhandled or mishandled exceptional conditions.

SI-11 Error Handling partial match

Requires generation of appropriate error messages on exceptional conditions, directly enforcing correct handling rather than silent or incorrect behavior.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices explicitly require proper exception and error handling during design and coding.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance verifies correct handling of exceptional conditions.

A.5.37 Documented operating procedures partial match
degrades

Documented operating procedures may specify exception handling but do not guarantee implementation.

A.8.15 Logging partial match
finds

Logging captures unhandled exceptions, aiding detection but not preventing the weakness.

A.8.16 Monitoring activities partial match
finds

Monitoring can surface unhandled exceptions but does not enforce proper handling.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates exception-handling requirements and testing that directly prevent improper handling of exceptional conditions.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly include handling of error and exceptional conditions.

References