CVE-2022-3775

Heap corruption via unchecked glyph dimensions

Published Dec 19, 2022 · Updated May 27, 2026

Out-of-bounds write in GNU GRUB 2.06 and earlier allows local users to corrupt heap memory via crafted Unicode glyph sequences. The font renderer accepts glyph width and height values that exceed the allocated bitmap dimensions, so glyph blitting writes beyond a heap buffer. Local low-privileged access is required; triggering the sequence can crash the bootloader, while arbitrary code execution remains unproven.

CVSS severity7.1
High
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in GNU GRUB 2.06 and earlier allows local users to corrupt heap memory via crafted Unicode glyph sequences. The font renderer accepts glyph width and height values that exceed the allocated bitmap dimensions, so glyph blitting writes beyond a heap buffer. Local low-privileged access is required; triggering the sequence can crash the bootloader, while arbitrary code execution remains unproven.

The record

CVE
CVE-2022-3775
Published
Dec 19, 2022
Updated
May 27, 2026
Vendor
The GnuPG Project
Product
GNU GRUB
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 19, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=All up to 2.06

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The GnuPG Project · GNU GRUBversion=All up to 2.06

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
6.3GNU GRUB upstreamCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
7.1CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
7.1CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo