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CVE-2025-0686· NVD / CVE Program· CNA redhat

Grub2: romfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat

Noroxi assessment

Priority: Monitor (action score 25/100)

  • 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: 0.27% (FIRST EPSS).
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: azl3 grub2 2.06-24 on Azure Linux 3.0 2.06-25; azl3 grub2 2.06-25 on Azure Linux 3.0 2.06-25; cbl2 grub2 2.06-14 on CBL Mariner 2.0 2.06-15.

Low priority for now. Upgrade to azl3 grub2 2.06-24 on Azure Linux 3.0 2.06-25; azl3 grub2 2.06-25 on Azure Linux 3.0 2.06-25; cbl2 grub2 2.06-14 on CBL Mariner 2.0 2.06-15 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

A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

MediumCVSS 6.4 · v3.1—No exploit Fix available
Published
Mar 3, 2025
Updated
Jun 29, 2026
EPSS
0.3% · 19th percentile

Report tools

JSON

Action score

25

Monitor

Low priority for now.

CVSS
25 / 40 · 6.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.4
CNA · redhat
6.4
agree

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-2025-0686

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.

VendorProduct
gnugrub2

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • gnu grub2up to 2.12 inclusive

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.

  • Red Hat Red Hat Enterprise Linux 10

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 9

    • all versionsunknown

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsunknown

  • www.gnu.org/software/grub/ grub2

    • up to and including 2.12affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12grub2before 2.06-13+deb12u22.06-13+deb12u2
Debian:13grub2before 2.12-62.12-6
openSUSE:Tumbleweedgrub2before 2.12-35.12.12-35.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSgrub2before 2.04-150300.22.52.32.04-150300.22.52.3
SUSE:Linux Enterprise Micro 5.1grub2before 2.04-150300.3.11.12.04-150300.3.11.1
SUSE:Linux Enterprise Micro 5.3grub2before 2.06-150400.11.55.22.06-150400.11.55.2
SUSE:Linux Enterprise Micro 5.5grub2before 2.06-150500.29.43.22.06-150500.29.43.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6grub2before 2.12-150600.8.18.22.12-150600.8.18.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6grub2before 2.12-150600.8.18.22.12-150600.8.18.2
SUSE:Linux Enterprise Server 12 SP5-LTSSgrub2before 2.02-181.22.02-181.2
SUSE:Linux Micro 6.0grub2before 2.12~rc1-6.12.12~rc1-6.1
SUSE:Linux Micro 6.1grub2before 2.12-slfo.1.1_2.12.12-slfo.1.1_2.1

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
  • CVE-2022-28733Integer underflow in grub_net_recv_ip4_packets
    32Monitor
  • 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 / packageFixed versionSource
azl3 grub2 2.06-24 on Azure Linux 3.02.06-25 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 grub2 2.06-25 on Azure Linux 3.02.06-25 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 grub2 2.06-14 on CBL Mariner 2.02.06-15 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 grub2 2.06-15 on CBL Mariner 2.02.06-15 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 grub2 2.06-15 on CBL-Mariner 2.02.06-15 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:grub22.06-13+deb12u2 · Debian:12Package registry (OSV)
opensuse:grub22.12-150600.8.18.2 · openSUSE:Leap 15.6Package registry (OSV)
suse:grub22.04-150300.3.11.1 · SUSE:Linux Enterprise Micro 5.1Package registry (OSV)
suse:grub22.12-150600.8.18.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package 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.

EPSS, last 120 days

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 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.

  • CVE-2024-457820 days apartGrub2: fs/hfs: strcpy() using the volume name (fs/hfs.c:382)
    31Monitor
  • CVE-2025-11250 days apartGrub2: fs/hfs: integer overflow may lead to heap based out-of-bounds write
    31Monitor
  • CVE-2024-457800 days apartGrub2: fs/tar: integer overflow causes heap oob write
    26Monitor
  • CVE-2024-4577712 days apartGrub2: grub-core/gettext: integer overflow leads to heap oob write.
    26Monitor
  • CVE-2025-06840 days apartGrub2: reiserfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data
    25Monitor
  • CVE-2025-06850 days apartGrub2: jfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data
    25Monitor

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

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

nvd-primary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

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