Description
gdm3 versions before 3.36.2 or 3.38.2 would start gnome-initial-setup if gdm3 can't contact the accountservice service via dbus in a timely manner; on Ubuntu (and potentially derivatives) this could be be chained with an additional issue that could allow a local user to create a new privileged account.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Gnome | GDM3 | 3.36 – < 3.36.4, 3.38 – < 3.38.2 | 3.36.4 |
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 | gdm3 | 3.38.2-1 | — |
| Debian 13 | gdm3 | 3.38.2-1 | — |
| Debian 12 | gdm3 | 3.38.2-1 | — |
| Debian 9 | gdm3 | 3.22.3-3+deb9u3 | DLA-2434-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | gdm3 | 3.36.3-0ubuntu0.20.04.2 | USN-4614-1 |
| Ubuntu 18.04 LTS | gdm3 | 3.28.3-0ubuntu18.04.6 | USN-4614-1 |
| Ubuntu 16.04 LTS | gdm3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | gdm | 1:3.28.3-39.el8 | RHSA-2021:1586 |
| RHEL 8 | glib2 +5 | 2.56.4-9.el8 | RHSA-2021:1586 |
| RHEL 8 | webkit2gtk3 +3 | 2.30.4-1.el8 | RHSA-2021:1586 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | OpenEXR-libs +1 | 2.2.0-12.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | accountsservice-devel | 0.6.55-1.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | atkmm +2 | 2.24.2-7.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | cairomm +2 | 1.12.0-8.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | chrome-gnome-shell | 10.1-7.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | dleyna-core +1 | 0.6.0-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | enchant2 +1 | 2.2.3-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gamin +1 | 0.1.10-32.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | geoclue2 +3 | 2.5.5-2.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | geocode-glib +1 | 3.26.0-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gjs +1 | 1.56.2-5.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | glib2-doc +1 | 2.56.4-9.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | glibmm24 +2 | 2.56.0-2.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gnome-boxes | 3.36.5-8.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gnome-photos +1 | 3.28.1-4.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gnome-terminal +1 | 3.28.3-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gtk-doc | 1.28-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gtk2 +4 | 2.24.32-5.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gtkmm24 +2 | 2.24.5-6.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gtkmm30 +2 | 3.22.2-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | gvfs +10 | 1.36.2-11.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | libdazzle +1 | 3.28.5-2.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | libepubgen +1 | 0.1.0-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | libsass +1 | 3.4.5-6.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | libsigc++20 +2 | 2.10.0-6.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | libvisual +1 | 1:0.4.0-25.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | mutter-devel | 3.32.2-57.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | nautilus +2 | 3.28.1-15.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | pangomm +2 | 2.40.1-6.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | soundtouch +1 | 2.0.0-3.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | vala +1 | 0.40.19-2.el8 | ALSA-2021:1586 |
| AlmaLinux 8 | woff2 +1 | 1.0.2-5.el8 | ALSA-2021:1586 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | OpenEXR | 2.2.0-12.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | accountsservice | 0.6.55-1.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | atkmm | 2.24.2-7.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | cairomm | 1.12.0-8.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | chrome-gnome-shell | 10.1-7.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | dleyna-core +1 | 0.6.0-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | enchant2 | 2.2.3-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gamin | 0.1.10-32.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gdm | 1:3.28.3-39.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | geoclue2 | 2.5.5-2.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | geocode-glib | 3.26.0-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gjs | 1.56.2-5.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | glibmm24 | 2.56.0-2.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-boxes | 3.36.5-8.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-control-center | 3.28.2-27.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-online-accounts | 3.28.2-2.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-photos | 3.28.1-4.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-settings-daemon | 3.32.0-14.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-shell | 3.32.2-30.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-software | 3.36.1-5.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gnome-terminal | 3.28.3-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gtk-doc | 1.28-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gtk2 | 2.24.32-5.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gtkmm24 | 2.24.5-6.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gtkmm30 | 3.22.2-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | gvfs | 1.36.2-11.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | libdazzle | 3.28.5-2.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | libepubgen | 0.1.0-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | libsass | 3.4.5-6.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | libsigc++20 | 2.10.0-6.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | libvisual | 1:0.4.0-25.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | mutter | 3.32.2-57.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | nautilus | 3.28.1-15.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | pangomm | 2.40.1-6.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | soundtouch | 2.0.0-3.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | vala | 0.40.19-2.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | webkit2gtk3 | 2.30.4-1.el8 | RLSA-2021:1586 |
| Rocky Linux 8 | woff2 | 1.0.2-5.el8 | RLSA-2021:1586 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | gdm | 3.34.1-8.9.1 | SUSE-SU-2020:3333-1 |
| SLES 15 SP1 | gdm | 3.26.2.1-13.39.2 | SUSE-SU-2020:3799-1 |
| SLES 12 SP5 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES 12 SP4 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES 12 SP3 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES for SAP 12 SP5 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES for SAP 12 SP4 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES for SAP 12 SP3 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SLES for SAP 12 SP2 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE OpenStack Cloud Crowbar 9 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE OpenStack Cloud Crowbar 8 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE OpenStack Cloud 9 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE OpenStack Cloud 8 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE OpenStack Cloud 7 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE HPE Helion OpenStack 8 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
| SUSE Enterprise Storage 5 | gdm | 3.10.0.1-54.17.2 | SUSE-SU-2020:3614-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | gdm | 41.0-1.1 | openSUSE-SU-2024:11547-1 |
| openSUSE Leap 15.2 | gdm | 3.34.1-lp152.6.9.1 | openSUSE-SU-2020:1961-1 |
| openSUSE Leap 15.1 | gdm | 3.26.2.1-lp151.16.10.1 | openSUSE-SU-2020:2264-1 |
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
-
za970120604/CVE-2020-16125-Reproduction ★ 1 · Aug 3, 2023
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 11
- ALSA-2021:1586 Moderate: GNOME security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:1586 Red Hat Security Advisory: GNOME security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4614-1 gdm3 vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2434-1 gdm3 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:1586 Moderate: GNOME security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- openSUSE-SU-2020:2264-1 Security update for gdm SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11547-1 gdm-41.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3614-1 Security update for gdm SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3333-1 Security update for gdm SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3799-1 Security update for gdm SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1961-1 Security update for gdm SUSE / openSUSE Security Updates · Feb 4, 2026