# CVE-2026-62425: buffer overruns in libfsimage iso9660 handling

> Attackers can trigger buffer overruns in Xen's libfsimage iso9660 driver via crafted disk images, potentially leading to code execution or denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 28 Jul 2026
- **Updated:** 28 Jul 2026
- **Also known as:** ALPINE-CVE-2026-62425, DEBIAN-CVE-2026-62425, GHSA-r2qc-jvxx-r42q, UBUNTU-CVE-2026-62425

## What is CVE-2026-62425?

CVE-2026-62425 is a medium-severity memory corruption vulnerability in Xen, published on 28 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]

The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver
derives several lengths directly from attacker-controlled on-disk fields
without validating them:

 * The directory loop itself assumes a good record length.  This is
   CVE-2026-42494.

 * The calculation of the System Use area may underflow.  This is
   CVE-2026-42495.

 * The Rock Ridge extension loop assumes a good (inner) record length.
   This is CVE-2026-62423.

 * The Rock Ridge NM record processing assumes a good entry length.
   This is CVE-2026-62424.

 * The Rock Ridge CE record processing assumes a good size and offset.
   This is CVE-2026-62425.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-62425?


## How do I fix CVE-2026-62425?

Apply the vendor's patch.

## Is CVE-2026-62425 being exploited?

There is no known exploitation of CVE-2026-62425 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62425 and fix it if it is affected.

What it is: CVE-2026-62425 is a medium-severity memory corruption vulnerability in Xen, published on 28 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-62425 in the wild and no public exploit code.

Affected product: 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-2026-62425/ (Markdown: https://insights.sbomify.com/CVE-2026-62425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62425
- OSV: https://osv.dev/vulnerability/CVE-2026-62425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-62425/
Summaries are generated and may contain mistakes; the official description above is the record.