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Vulnerability · Published Nov 18, 2025 · Assigned by redhat

CVE-2025-61661Grub2: grub2: out-of-bounds write via malicious usb device

Medium 4.8

In plain English

A medium-severity security flaw in grub2 from GNU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.2%top 89.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12grub2no fix listedDEBIAN-CVE-2025-61661
Debian:13grub2no fix listedDEBIAN-CVE-2025-61661
Debian:14grub22.14-1DEBIAN-CVE-2025-61661
Ubuntu:22.04:LTSgrub2-signedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:24.04:LTSgrub2-signedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:25.10grub2-signedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:26.04:LTSgrub2-signedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:26.10grub2-signedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:22.04:LTSgrub2-unsignedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:24.04:LTSgrub2-unsignedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:25.10grub2-unsignedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:26.04:LTSgrub2-unsignedno fix listedUBUNTU-CVE-2025-61661
Ubuntu:26.10grub2-unsignedno fix listedUBUNTU-CVE-2025-61661

Affected products (as reported)

VendorProductVersions
GNU grub2 0 – through 2.14
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 4 see references

Weakness: CWE-131 · Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

References