Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Gnu | Grub2 | <= 2.12 |
Related Weaknesses (CWE)
References
- https://access.redhat.com/security/cve/CVE-2025-0686Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2346121Issue Tracking
FAQ
What is CVE-2025-0686?
CVE-2025-0686 is a vulnerability with a CVSS score of 6.4 (MEDIUM). 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 intern...
How severe is CVE-2025-0686?
CVE-2025-0686 has been rated MEDIUM with a CVSS base score of 6.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-0686?
Check the references section above for vendor advisories and patch information. Affected products include: Gnu Grub2.