{"id":"CVE-2025-0686","title":"A flaw was found in grub2","summary":"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 improperl…","severity":"medium","cvss":6.4,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"gnu","product":"grub2","affected":["grub2 <= 2.12"],"published":"2025-03-03","updated":"2026-06-26","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-0686","references":[{"url":"https://access.redhat.com/security/cve/CVE-2025-0686","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2346121","label":"secalert@redhat.com"},{"url":"https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00278,"epssPercentile":0.20419,"ingestedAt":"2026-06-26T16:43:13.414Z","slug":"CVE-2025-0686","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `grub2 <= 2.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":35.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}