Vulnerability in Gnu Grub2
CVE-2025-61661
A vulnerability has been identified in the GRUB (Grand Unified Bootloader) component. This flaw occurs because the bootloader mishandles string conversion when reading information from a USB device, allowing an attacker to exploit inconsistent length values. A local attacker can connect a maliciously configured USB device during the boot sequence to trigger this issue. A successful exploitation may lead GRUB to crash, leading to a Denial of Service. Data corruption may be also possible, although given the complexity of the exploit the impact is most likely limited.
EPSS: 0.002 (8.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H.
Affected products
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-61661?
- CVE-2025-61661 is a medium-severity vulnerability in Gnu Grub2, classified under Incorrect Calculation of Buffer Size. CVSS score: 4.8/10. Published 2025-11-18.
- How severe is CVE-2025-61661?
- Medium severity. CVSS v3 base score is 4.8 out of 10.