# CVE-2025-0684: Grub2: reiserfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data

Status: published. Published: 2025-03-03. Updated: 2026-11-05.

A flaw was found in grub2. When performing a symlink lookup from a reiserfs filesystem, grub's reiserfs fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciouly 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_reiserfs_read_symlink() will call grub_reiserfs_read_real() with a overflown length parameter, leading to a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution, by-passing secure boot protections.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. (source: CNA: redhat)

## Affected products and versions

-  /  (grub2): ≥ 0; ≤ 2.12 (affected, semver). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.4 (medium); CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.29% as of 2026-11-05; percentile 21.28%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2025-0684 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2346119 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2025-0684; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-0684; retrieved 2026-11-05; source updated Not reported

Revision: 6a4e1a7c7c1a32eb53e4e112d3a00176fc8e7bff98c8710b2ce26d61e990184f

Canonical: https://y2.dev/cve/CVE-2025-0684

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