# CVE-2025-0686: Grub2: romfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat

> An integer overflow in GRUB2's romfs module allows heap-based out-of-bounds writes, enabling arbitrary code execution and secure boot bypass.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Mar 2025
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-57672, AZL-57700, BELL-CVE-2025-0686, DEBIAN-CVE-2025-0686, GHSA-5pg5-wv5r-mmj7, UBUNTU-CVE-2025-0686

## What is CVE-2025-0686?

CVE-2025-0686 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 3 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-0686?

It affects 1 product.


Products: Gnu Grub2.

## How do I fix CVE-2025-0686?

Apply the vendor's patch.

## Is CVE-2025-0686 being exploited?

There is no known exploitation of CVE-2025-0686 in the wild and no public exploit code.

## Other vulnerabilities in Red Hat Enterprise Linux 10

- [CVE-2024-56737](https://insights.sbomify.com/CVE-2024-56737/): Memory corruption in GRUB2 (high 8.8)
- [CVE-2022-28733](https://insights.sbomify.com/CVE-2022-28733/): Integer underflow in grub_net_recv_ip4_packets (high 8.1)
- [CVE-2022-28734](https://insights.sbomify.com/CVE-2022-28734/): Out-of-bounds write when handling split HTTP headers (high 8.1)
- [CVE-2025-61662](https://insights.sbomify.com/CVE-2025-61662/): Grub2: missing unregister call for gettext command may lead to use-after-free (high 7.8)
- [CVE-2024-45782](https://insights.sbomify.com/CVE-2024-45782/): Grub2: fs/hfs: strcpy() using the volume name (fs/hfs.c:382) (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-0686 and fix it if it is affected.

What it is: CVE-2025-0686 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 3 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-0686 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2025-0686/ (Markdown: https://insights.sbomify.com/CVE-2025-0686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-0686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-0686
- OSV: https://osv.dev/vulnerability/CVE-2025-0686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-0686/
Summaries are generated and may contain mistakes; the official description above is the record.