CVE-2025-0685
When reading data from a jfs filesystem, grub's jfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows.
Does this matter?
Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own.
Description
A flaw was found in grub2. When reading data from a jfs filesystem, grub's jfs filesystem 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_jfs_lookup_symlink() function will write past the internal buffer length during grub_jfs_read_file(). This issue can be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.29% probability · 21th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- gnu/grub2
- Source
- secalert@redhat.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.