How severe is CVE-2025-61661?

CVE-2025-61661 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2025-61661 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-61661?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-61661 have an EU (EUVD) identifier?

Yes. CVE-2025-61661 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198081.

When was CVE-2025-61661 published?

CVE-2025-61661 was published on 2025-11-18 and last updated on 2026-06-30.

CVE-2025-61661

CVE-2025-61661 is a medium-severity vulnerability with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-131.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-198081
Weakness: CWE-131
Published: 2025-11-18
Last modified: 2026-06-30

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-61661?: CVE-2025-61661 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2025-61661 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-61661?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-61661 have an EU (EUVD) identifier?: Yes. CVE-2025-61661 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198081.
When was CVE-2025-61661 published?: CVE-2025-61661 was published on 2025-11-18 and last updated on 2026-06-30.

References

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