Grub2: grub2: out-of-bounds write via malicious usb device
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.
- Published
- Nov 18, 2025
- Updated
- Sep 1, 2026
- EPSS
- 0.2% · 8th percentile
- CWE
- CWE-131
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Report tools
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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
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.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | grub2 | all versions | — |
| Debian:14 | grub2 | before 2.14-1 | 2.14-1 |
| openSUSE:Leap 16.0 | grub2 | before 2.12-160000.3.1 | 2.12-160000.3.1 |
| openSUSE:Tumbleweed | grub2 | before 2.12-67.1 | 2.12-67.1 |
| SUSE:Linux Enterprise Micro 5.2 | grub2 | before 2.04-150300.22.61.1 | 2.04-150300.22.61.1 |
| SUSE:Linux Enterprise Micro 5.3 | grub2 | before 2.06-150400.11.66.1 | 2.06-150400.11.66.1 |
| SUSE:Linux Enterprise Micro 5.5 | grub2 | before 2.06-150500.29.59.1 | 2.06-150500.29.59.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | grub2 | before 2.12-150600.8.44.2 | 2.12-150600.8.44.2 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | grub2 | before 2.12-150600.8.44.2 | 2.12-150600.8.44.2 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | grub2 | before 2.12-150700.19.19.1 | 2.12-150700.19.19.1 |
| SUSE:Linux Enterprise Server 16.0 | grub2 | before 2.12-160000.3.1 | 2.12-160000.3.1 |
| SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | grub2 | before 2.02-193.1 | 2.02-193.1 |
| SUSE:Linux Micro 6.1 | grub2 | before 2.12-slfo.1.1_3.1 | 2.12-slfo.1.1_3.1 |
Same product
gnu: all recordsOther 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
- CVE-2022-28733Integer underflow in grub_net_recv_ip4_packets32Monitor
- CVE-2021-20233A flaw was found in grub2 in versions prior to 2.06.32Monitor
- CVE-2020-25632A flaw was found in grub2 in versions prior to 2.06.32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:grub2 | 2.14-1 · Debian:14 | Package registry (OSV) |
| opensuse:grub2 | 2.12-150600.8.44.2 · openSUSE:Leap 15.6 | Package registry (OSV) |
| suse:grub2 | 2.12-150600.8.44.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP6 | Package registry (OSV) |
| suse:grub2 | 2.12-slfo.1.1_3.1 · SUSE:Linux Micro 6.1 | Package 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, 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 SizeCVSS 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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- access.redhat.com/security/cve/CVE-2025-61661
- bugzilla.redhat.com/show_bug.cgi?id=2413827
- www.openwall.com/lists/oss-security/2025/11/18/8
Vendor advisories and official records. Exploit/PoC links are deliberately left out.