CVE-2025-0686
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.
How to fix CVE-2025-0686
To remediate CVE-2025-0686, upgrade the affected package to a fixed version below.
- —upgrade to 2.06-3~deb11u7 or later
Is CVE-2025-0686 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2.06-3~deb11u7
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |