CVE-2025-0689

Secure Boot bypass via oversized UDF sector read

Published Mar 3, 2025 · Updated Jun 29, 2026

Heap-based buffer overflow in GNU GRUB 2.12 and earlier allows local users to execute code via a crafted UDF filesystem image. The UDF module's grub_udf_read_block() trusts attacker-controlled length metadata and reads disk sectors larger than its allocated heap buffer. Exploitation requires GRUB to process the malicious image during boot and can corrupt bootloader state, enabling code execution that bypasses Secure Boot.

CVSS severity7.8
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in GNU GRUB 2.12 and earlier allows local users to execute code via a crafted UDF filesystem image. The UDF module's grub_udf_read_block() trusts attacker-controlled length metadata and reads disk sectors larger than its allocated heap buffer. Exploitation requires GRUB to process the malicious image during boot and can corrupt bootloader state, enabling code execution that bypasses Secure Boot.

The record

CVE
CVE-2025-0689
Published
Mar 3, 2025
Updated
Jun 29, 2026
Vendor
The GnuPG Project
Product
GNU GRUB
Classifications
CWE-120, T1542.003
Attack vector
local
Privileges
unauthenticated

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 privilegesunauthenticated

What is affected?

The GnuPG Project · GNU GRUBversion=0 <=2.12

Published CVSS scores

7.8NISTCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1542.003Bootkit

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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