CVE-2022-2601

Secure Boot bypass via malformed PF2 font

Published Dec 14, 2022 · Updated May 27, 2026

Heap buffer overflow in GNU GRUB 2.06 and earlier allows local users to bypass Secure Boot through a crafted PF2 font. In grub_font_construct_glyph(), integer overflow in the max_glyph_size calculation allocates a glyph buffer that is too small, leading to a heap out-of-bounds write. Exploitation requires the crafted font to be loaded during boot and can undermine the boot trust boundary without prior GRUB privileges.

CVSS severity8.6
High
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in GNU GRUB 2.06 and earlier allows local users to bypass Secure Boot through a crafted PF2 font. In grub_font_construct_glyph(), integer overflow in the max_glyph_size calculation allocates a glyph buffer that is too small, leading to a heap out-of-bounds write. Exploitation requires the crafted font to be loaded during boot and can undermine the boot trust boundary without prior GRUB privileges.

The record

CVE
CVE-2022-2601
Published
Dec 14, 2022
Updated
May 27, 2026
Vendor
The GnuPG Project
Product
GNU GRUB
Classifications
CWE-787, CWE-122, T1542.003
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 14, 2022CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=grub2 2.06 and lower

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The GnuPG Project · GNU GRUBversion=grub2 2.06 and lower

Published CVSS scores

8.6CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
8.6NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-122Heap-based Buffer Overflow
T1542.003Pre-OS Boot: Bootkit

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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