What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-03-03 · updated 2026-10-21
• Weakness: CWE-787

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.

Affected products

• grub2: through 2.12

References

• https://access.redhat.com/security/cve/CVE-2025-0686
• https://bugzilla.redhat.com/show_bug.cgi?id=2346121
• https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html

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