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NVD / CVE Program· CNA redhat

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

Noroxi assessment

Priority: Monitor (action score 19/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
  • Physical access to the device is required. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: azl3 grub2 2.06-25 on Azure Linux 3.0 2.06-26; azl3 grub2 2.06-26 on Azure Linux 3.0 2.06-26; cbl2 grub2 2.06-15 on CBL Mariner 2.0 2.06-16.

Low priority for now. Upgrade to azl3 grub2 2.06-25 on Azure Linux 3.0 2.06-26; azl3 grub2 2.06-26 on Azure Linux 3.0 2.06-26; cbl2 grub2 2.06-15 on CBL Mariner 2.0 2.06-16 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 4.8 · v3.1—No exploit Fix available
Published
Nov 18, 2025
Updated
Nov 5, 2026
EPSS
0.2% · 10th percentile

Report tools

JSON

Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
4.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-61661

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • GNU grub2

    • up to and including 2.14affected · semver

  • Red Hat Red Hat Enterprise Linux 10

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9

    • all versionsaffected

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsaffected
    • all versionsaffected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12grub2from 0—
Debian:14grub2before 2.14-12.14-1
openSUSE:Leap 15.6grub2before 2.12-150600.8.44.22.12-150600.8.44.2
openSUSE:Leap 16.0grub2before 2.12-160000.3.12.12-160000.3.1
openSUSE:Tumbleweedgrub2before 2.12-67.12.12-67.1
SUSE:Linux Enterprise Micro 5.2grub2before 2.04-150300.22.61.12.04-150300.22.61.1
SUSE:Linux Enterprise Micro 5.3grub2before 2.06-150400.11.66.12.06-150400.11.66.1
SUSE:Linux Enterprise Micro 5.5grub2before 2.06-150500.29.59.12.06-150500.29.59.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6grub2before 2.12-150600.8.44.22.12-150600.8.44.2
SUSE:Linux Enterprise Module for Basesystem 15 SP7grub2before 2.12-150700.19.19.12.12-150700.19.19.1
SUSE:Linux Enterprise Server 16.0grub2before 2.12-160000.3.12.12-160000.3.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5grub2before 2.02-193.12.02-193.1
SUSE:Linux Micro 6.1grub2before 2.12-slfo.1.1_3.12.12-slfo.1.1_3.1

Same product

gnu: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-56737GNU GRUB (aka GRUB2) through 2.12 has a heap-based buffer overflow in fs/hfs.c via crafted sblock data in an HFS filesystem.
    35Monitor
  • CVE-2022-2601A buffer overflow was found in grub_font_construct_glyph().
    34Monitor
  • CVE-2020-10713A flaw was found in grub2, prior to version 2.06.
    33Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-54770Nov 18, 2025 · Grub2: use-after-free in net_set_vlan
    19Monitor
  • ← EarlierCVE-2025-54771Nov 18, 2025 · Grub2: use-after-free in grub_file_close()
    19Monitor
  • Later →CVE-2025-61662Nov 18, 2025 · Grub2: missing unregister call for gettext command may lead to use-after-free
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 grub2 2.06-25 on Azure Linux 3.02.06-26 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 grub2 2.06-26 on Azure Linux 3.02.06-26 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 grub2 2.06-15 on CBL Mariner 2.02.06-16 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 grub2 2.06-16 on CBL Mariner 2.02.06-16 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:grub22.14-1 · Debian:14Package registry (OSV)
opensuse:grub22.12-150600.8.44.2 · openSUSE:Leap 15.6Package registry (OSV)
suse:grub22.12-150600.8.44.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:grub22.12-slfo.1.1_3.1 · SUSE:Linux Micro 6.1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Physical access to the device is required.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Physical
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
High

Weakness class (CWE)

CWE-131 · Incorrect Calculation of Buffer Size

CVSS vector

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records