# CVE-2025-27465: x86: Incorrect stubs exception handling for flags recovery

> A flaw in Xen's x86 exception handling for emulated instructions causes fatal crashes instead of graceful recovery, leading to denial of service.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Jul 2025
- **Updated:** 4 Nov 2025
- **Also known as:** ALPINE-CVE-2025-27465, DEBIAN-CVE-2025-27465, GHSA-2vp3-crwq-3fg5, SUSE-SU-2025:02471-1, UBUNTU-CVE-2025-27465, openSUSE-SU-2025:15342-1

## What is CVE-2025-27465?

CVE-2025-27465 is a medium-severity denial of service vulnerability in Xen Xen, published on 16 Jul 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### 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.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2025-27465?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `xen` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 4.12.4_62-3.130.1 |
| `xen` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 4.12.4_62-3.130.1 |
| `xen` | openSUSE:Tumbleweed | All versions | 4.20.1_02-1.1 |

Products: Xen Xen.

## How do I fix CVE-2025-27465?

Apply the vendor's patch.

## Is CVE-2025-27465 being exploited?

There is no known exploitation of CVE-2025-27465 in the wild and no public exploit code.

## Other vulnerabilities in Xen Xen

- [CVE-2017-10912](https://insights.sbomify.com/CVE-2017-10912/): Privilege escalation in n/a (critical 10.0)
- [CVE-2017-10918](https://insights.sbomify.com/CVE-2017-10918/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10920](https://insights.sbomify.com/CVE-2017-10920/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-10921](https://insights.sbomify.com/CVE-2017-10921/): Memory corruption in n/a (critical 10.0)
- [CVE-2025-27466](https://insights.sbomify.com/CVE-2025-27466/): Mutiple vulnerabilities in the Viridian interface (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-27465 and fix it if it is affected.

What it is: CVE-2025-27465 is a medium-severity denial of service vulnerability in Xen Xen, published on 16 Jul 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-27465 in the wild and no public exploit code.

Affected product: Xen Xen. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-27465/ (Markdown: https://insights.sbomify.com/CVE-2025-27465/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27465
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27465
- OSV: https://osv.dev/vulnerability/CVE-2025-27465

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-27465/
Summaries are generated and may contain mistakes; the official description above is the record.