Description
A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | grub2 | grub 2.06 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | grub2 | 2.04-16 | — |
| Debian 13 | grub2 | 2.04-16 | — |
| Debian 12 | grub2 | 2.04-16 | — |
| Debian 10 | grub2 | 2.02+dfsg1-20+deb10u4 | DSA-4867-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | grub2-signed | 1.167.2 | USN-4992-1 |
| Ubuntu 20.04 LTS | grub2-unsigned | 2.04-1ubuntu44.2 | USN-4992-1 |
| Ubuntu 18.04 LTS | grub2-signed | 1.167~18.04.5 | USN-4992-1 |
| Ubuntu 18.04 LTS | grub2-unsigned | 2.04-1ubuntu44.1.2 | USN-4992-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | grub2-signed | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | fwupd | 1.5.9-1.el8_4 | RHSA-2021:2566 |
| RHEL 8 | grub2 +18 | 1:2.02-90.el8_3.1 | RHSA-2021:0696 |
| RHEL 8 | shim +3 | 15.4-2.el8_1 | RHSA-2021:1734 |
| RHEL 8 | shim-unsigned-aarch64 | 15-7.el8_1 | RHSA-2021:1734 |
| RHEL 8 | shim-unsigned-x64 | 15.4-4.el8_1 | RHSA-2021:1734 |
| RHEL 7 | grub2 +18 | 1:2.02-0.87.el7_9.2 | RHSA-2021:0699 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | fwupd | 1.1.4-9.el8_2 | RHSA-2021:2790 |
| RHEL 8.2 EUS | grub2 +18 | 1:2.02-87.el8_2.3 | RHSA-2021:0697 |
| RHEL 8.2 EUS | shim +3 | 15.4-2.el8_1 | RHSA-2021:2790 |
| RHEL 8.2 EUS | shim-unsigned-aarch64 | 15-7.el8_1 | RHSA-2021:2790 |
| RHEL 8.2 EUS | shim-unsigned-x64 | 15.4-4.el8_1 | RHSA-2021:2790 |
| RHEL 8.1 EUS | fwupd | 1.1.4-4.el8_1 | RHSA-2021:3675 |
| RHEL 8.1 EUS | grub2 +18 | 1:2.02-87.el8_1.2 | RHSA-2021:0698 |
| RHEL 8.1 EUS | shim +3 | 15.4-2.el8_1 | RHSA-2021:3675 |
| RHEL 8.1 EUS | shim-unsigned-aarch64 | 15-7.el8_1 | RHSA-2021:3675 |
| RHEL 8.1 EUS | shim-unsigned-x64 | 15.4-4.el8_1 | RHSA-2021:3675 |
| RHEL 7.7 EUS | grub2 +18 | 1:2.02-0.86.el7_7.3 | RHSA-2021:0700 |
| RHEL 7.6 EUS | grub2 +18 | 1:2.02-0.86.el7_6.3 | RHSA-2021:0701 |
| RHEL 7.4 TUS | grub2 +16 | 1:2.02-0.86.el7_4.2 | RHSA-2021:0702 |
| RHEL 7.4 E4S | grub2 +17 | 1:2.02-0.86.el7_4.2 | RHSA-2021:0702 |
| RHEL 7.4 AUS | grub2 +16 | 1:2.02-0.86.el7_4.2 | RHSA-2021:0702 |
| RHEL 7.3 AUS | grub2 +16 | 1:2.02-0.86.el7_3.2 | RHSA-2021:0703 |
| RHEL 7.2 AUS | grub2 +16 | 1:2.02-0.86.el7_2.2 | RHSA-2021:0704 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | shim-unsigned-aarch64 | 15-7.el8_1.alma | ALSA-2021:1734 |
| AlmaLinux 8 | shim-unsigned-x64 | 15.4-4.el8_1.alma | ALSA-2021:1734 |
| AlmaLinux 8 | shim-x64 +2 | 15.4-2.el8_1.alma | ALSA-2021:1734 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | fwupd | 1.5.9-1.el8_4 | RLSA-2021:2566 |
| Rocky Linux 8 | shim-unsigned-aarch64 | 15-7.el8.1.1 | RLSA-2021:1734 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | grub2 | 2.04-9.34.1 | SUSE-SU-2021:0683-1 |
| SLES 15 SP1 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SLES 15 | grub2 | 2.02-19.66.1 | SUSE-SU-2021:0685-1 |
| SLES 12 SP5 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
| SLES 12 SP4 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
Show 21 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | grub2 | 2.02-4.69.1 | SUSE-SU-2021:0682-1 |
| SLES 12 SP2 | grub2 | 2.02-115.59.1 | SUSE-SU-2021:0679-1 |
| SLES 11 SP4 | grub2 | 2.02-0.66.26.1 | SUSE-SU-2021:14659-1 |
| SLES for SAP 15 SP1 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SLES for SAP 15 | grub2 | 2.02-19.66.1 | SUSE-SU-2021:0685-1 |
| SLES for SAP 12 SP5 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
| SLES for SAP 12 SP4 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
| SLES for SAP 12 SP3 | grub2 | 2.02-4.69.1 | SUSE-SU-2021:0682-1 |
| SLES for SAP 12 SP2 | grub2 | 2.02-115.59.1 | SUSE-SU-2021:0679-1 |
| SLE HPC 15 SP1 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SLE HPC 15 | grub2 | 2.02-19.66.1 | SUSE-SU-2021:0685-1 |
| SUSE OpenStack Cloud Crowbar 9 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
| SUSE OpenStack Cloud Crowbar 8 | grub2 | 2.02-4.69.1 | SUSE-SU-2021:0682-1 |
| SUSE OpenStack Cloud 9 | grub2 | 2.02-12.47.1 | SUSE-SU-2021:0681-1 |
| SUSE OpenStack Cloud 8 | grub2 | 2.02-4.69.1 | SUSE-SU-2021:0682-1 |
| SUSE OpenStack Cloud 7 | grub2 | 2.02-115.59.1 | SUSE-SU-2021:0679-1 |
| SUSE Manager Server 4.0 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SUSE Manager Retail Branch Server 4.0 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SUSE Manager Proxy 4.0 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
| SUSE HPE Helion OpenStack 8 | grub2 | 2.02-4.69.1 | SUSE-SU-2021:0682-1 |
| SUSE Enterprise Storage 6 | grub2 | 2.02-26.43.1 | SUSE-SU-2021:0684-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | grub2 | 2.06-7.1 | openSUSE-SU-2024:10824-1 |
| openSUSE Leap 15.2 | grub2 | 2.04-lp152.7.22.7 | openSUSE-SU-2021:0462-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | grub | 2.06-r0 | — |
| Alpine v3.23 | grub | 2.06-r0 | — |
| Alpine v3.22 | grub | 2.06-r0 | — |
| Alpine v3.21 | grub | 2.06-r0 | — |
| Alpine v3.20 | grub | 2.06-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | grub | 2.06-r0 | — |
| Alpine v3.18 | grub | 2.06-r0 | — |
| Alpine v3.17 | grub | 2.06-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | grub2 +17 | 1:2.06-2.amzn2.0.1 | ALAS2-2021-1684 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | grub2 | 2.06~rc1-7 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | grub2-pc +15 | 1:2.02-90.0.2.el8 | ELSA-2021-9077, ELSA-2021-0696 |
| Oracle Linux 7 | grub2 +14 | 1:2.02-0.87.0.7.el7 | ELSA-2021-9076, ELSA-2021-0699 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
pauljrowland/BootHoleFix ★ 0 · Jul 19, 2022
This script will remediate the BootHole bug identified in CVE-2020-25632 and/or CVE-2021-20233.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 33
- ALSA-2021:1734 Moderate: shim security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:3675 Red Hat Security Advisory: shim and fwupd security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:2790 Red Hat Security Advisory: shim and fwupd security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:2566 Red Hat Security Advisory: fwupd security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:1734 Red Hat Security Advisory: shim security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0704 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0702 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0703 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0701 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0699 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0700 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0698 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0696 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2021:0697 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- USN-4992-1 grub2-signed, grub2-unsigned vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-4867-1 grub2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:1734 Moderate: shim security update Rocky Linux Security Advisories · Feb 5, 2026
- RLSA-2021:2566 Moderate: fwupd security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2021:0681-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14659-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0462-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0682-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0679-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0683-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0684-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0685-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10824-1 grub2-2.06-7.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2-2021-1684 Moderate: grub2 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 29, 2024
- ICSA-21-336-06 Hitachi Energy APM Edge CISA ICS & IT advisories · Dec 2, 2021
- ELSA-2021-0699 Moderate: grub2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 5, 2021
- ELSA-2021-0696 Moderate: grub2 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 5, 2021
- ELSA-2021-9076 Important: grub2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 2, 2021
- ELSA-2021-9077 Important: grub2 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 2, 2021