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NVD / CVE Program· CNA redhat

CVE-2025-0677: Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks

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: 0.32% (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

Primary sources: NVD · CVE.org · FIRST EPSS

A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.

MediumCVSS 6.4 · v3.1—No exploit Fix available
Published
Feb 19, 2025
Updated
Oct 21, 2026
EPSS
0.3% · 25th 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
—
CNA · redhat
6.4
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.

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

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  • when exploit code appears or is weaponized
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  • 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.

  • Red Hat Red Hat Enterprise Linux 10

    • 1:2.12-15.el10_0 and laternot affected · rpm

  • 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

    • 1:2.06-104.el9_6 and laternot affected · rpm

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsaffected

  • 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
AlmaLinux:10grub2-commonbefore 1:2.12-15.el10_0.alma.11:2.12-15.el10_0.alma.1
AlmaLinux:10grub2-efi-aa64-modulesbefore 1:2.12-15.el10_0.alma.11:2.12-15.el10_0.alma.1
AlmaLinux:10grub2-efi-x64-modulesbefore 1:2.12-15.el10_0.alma.11:2.12-15.el10_0.alma.1
AlmaLinux:10grub2-pc-modulesbefore 1:2.12-15.el10_0.alma.11:2.12-15.el10_0.alma.1
AlmaLinux:10grub2-ppc64le-modulesbefore 1:2.12-15.el10_0.alma.11:2.12-15.el10_0.alma.1
AlmaLinux:9grub2-commonbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-aa64before 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-aa64-cdbootbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-aa64-modulesbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-x64before 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-x64-cdbootbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-efi-x64-modulesbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-pcbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-pc-modulesbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-ppc64lebefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-ppc64le-modulesbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-toolsbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-tools-efibefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-tools-extrabefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
AlmaLinux:9grub2-tools-minimalbefore 1:2.06-104.el9_6.alma.11:2.06-104.el9_6.alma.1
Debian:12grub2before 2.06-13+deb12u22.06-13+deb12u2
Debian:13grub2before 2.12-62.12-6
openSUSE:Leap 15.6grub2before 2.12-150600.8.18.22.12-150600.8.18.2
openSUSE:Tumbleweedgrub2before 2.12-35.12.12-35.1

+56

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-10230Samba: command injection in wins server hook script
    52Plan
  • CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection
    44Plan
  • CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-0622Feb 18, 2025 · Grub2: command/gpg: use-after-free due to hooks not being removed on module unload
    25Monitor
  • ← EarlierCVE-2025-1118Feb 19, 2025 · Grub2: commands/dump: the dump command is not in lockdown when secure boot is enabled
    17Monitor
  • Later →CVE-2024-8176Mar 14, 2025 · Libexpat: expat: improper restriction of xml entity expansion depth in libexpat
    30Monitor

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)
almalinux:grub2-common1:2.12-15.el10_0.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:grub2-efi-aa641:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-efi-aa64-cdboot1:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-efi-aa64-modules1:2.12-15.el10_0.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:grub2-efi-x641:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-efi-x64-cdboot1:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-efi-x64-modules1:2.12-15.el10_0.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:grub2-pc1:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-pc-modules1:2.12-15.el10_0.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:grub2-ppc64le1:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
almalinux:grub2-ppc64le-modules1:2.12-15.el10_0.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:grub2-tools1:2.06-104.el9_6.alma.1 · AlmaLinux:9Package registry (OSV)
debian:grub22.06-13+deb12u2 · Debian:12Package registry (OSV)
opensuse:grub22.12-150600.8.18.2 · openSUSE:Leap 15.6Package registry (OSV)
red hat:grub21:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-common1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-debuginfo1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-debugsource1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-aa641:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-aa64-cdboot1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-aa64-modules1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-x641:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-x64-cdboot1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-efi-x64-modules1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:grub2-emu-debuginfo1:2.12-15.el10_0 · Red Hat:enterprise_linux:10.0Package registry (OSV)

+4

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-2026-3842511 days apartQemu-kvm: hyperv/syndbg: missing mapped-length guard after cpu_physical_memory_map causes host oob write
    31Monitor
  • CVE-2026-18220525 days apartBinutils: binutils: out-of-bounds write in bfd dlx elf backend relocation processing
    31Monitor
  • CVE-2026-6507422 days apartDnsmasq: dnsmasq: denial of service due to out-of-bounds write in dhcp bootreply processing
    30Monitor
  • CVE-2026-19387536 days apartGstreamer: gstreamer1-plugins-bad-free: gstreamer: heap out-of-bounds write in adpcmdec ima/dvi adpcm decoder
    30Monitor
  • CVE-2026-59691505 days apartGstreamer1-plugins-bad-free: gstreamer: rfbsrc/librfb hextile heap out-of-bounds write with 16bpp framebuffer
    28Monitor
  • CVE-2024-457761 days apartGrub2: grub-core/gettext: integer overflow leads to heap oob write and read.
    26Monitor

Chain candidates

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

  • CVE-2025-438279 days apartGrub2: grub allow access to encrypted device through cli once root device is unlocked via tpm
    23Monitor

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-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.

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 (4 more)

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

All records