Vulnerability · Published Jul 16, 2025 · Assigned by XEN
CVE-2025-27465x86: Incorrect stubs exception handling for flags recovery
Medium 4.3
In plain English
A medium-severity security flaw in Xen from Xen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.18.5-r1 | ALPINE-CVE-2025-27465 |
| Alpine:v3.21 | xen | 4.19.2-r2 | ALPINE-CVE-2025-27465 |
| Alpine:v3.22 | xen | 4.20.1-r0 | ALPINE-CVE-2025-27465 |
| Alpine:v3.23 | xen | 4.20.1-r0 | ALPINE-CVE-2025-27465 |
| Alpine:v3.24 | xen | 4.20.1-r0 | ALPINE-CVE-2025-27465 |
| Debian:12 | xen | 4.17.5+72-g01140da4e8-1 | DSA-6068-1 |
| Debian:12 | xen | 4.17.5+72-g01140da4e8-1 | DEBIAN-CVE-2025-27465 |
| Debian:13 | xen | 4.20.2+7-g1badcf5035-0+deb13u1 | DEBIAN-CVE-2025-27465 |
| Debian:13 | xen | 4.20.2+7-g1badcf5035-0+deb13u1 | DSA-6068-1 |
| Debian:14 | xen | 4.20.2+7-g1badcf5035-1 | DEBIAN-CVE-2025-27465 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2025-27465 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2025-27465 |
| Ubuntu:25.10 | xen | no fix listed | UBUNTU-CVE-2025-27465 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2025-27465 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2025-27465 |
Affected products (as reported)
Weakness: CWE-755 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L