CVE-2025-27465

x86: Incorrect stubs exception handling for flags recovery

MEDIUM
4.3
CVSS Score
Published: July 16, 2025 at 09:08 AM UTC
Updated: June 17, 2026 at 09:03 AM UTC
1 product affected across 1 vendorXen

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

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 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Xen· Xenwordpress-plugin
95%
v ≥ 4.9.0
Vendor states this is fixed in consult Xen advisory XSA-470 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2025/07/01/1
PatchVendor Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://xenbits.xen.org/xsa/advisory-470.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-755

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