CVE-2025-0686

Code execution via ROMFS symlink heap overwrite

Published Mar 3, 2025 · Updated Jun 29, 2026

Integer overflow in GNU GRUB 2.12 and earlier allows local users to execute arbitrary code through a crafted ROMFS filesystem. The grub_romfs_read_symlink() path derives an allocation size from untrusted filesystem geometry without rejecting overflow, so grub_malloc() reserves too little before grub_disk_read() writes symlink data. High local privileges and GRUB access to the malicious filesystem are required; successful exploitation can corrupt critical bootloader data and bypass Secure Boot.

CVSS severity6.4
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in GNU GRUB 2.12 and earlier allows local users to execute arbitrary code through a crafted ROMFS filesystem. The grub_romfs_read_symlink() path derives an allocation size from untrusted filesystem geometry without rejecting overflow, so grub_malloc() reserves too little before grub_disk_read() writes symlink data. High local privileges and GRUB access to the malicious filesystem are required; successful exploitation can corrupt critical bootloader data and bypass Secure Boot.

The record

CVE
CVE-2025-0686
Published
Mar 3, 2025
Updated
Jun 29, 2026
Vendor
The GnuPG Project
Product
GNU GRUB
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The GnuPG Project · GNU GRUBversion=0 <=2.12

Published CVSS scores

4.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
6.4UbuntuCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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