CVE-2020-16126

accountsservice drops ruid, allows unprivileged users to send it signals

3.3 LowPublic exploitFix available

An Ubuntu-specific modification to AccountsService in versions before 0.6.55-0ubuntu13.2, among other earlier versions, improperly dropped the ruid, allowing untrusted users to send signals to AccountService, thus stopping it from handling D-Bus messages in a timely fashion.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: Low

Exploit likelihood

0.54%Down 1.3 points since Apr 14, 2021

What each source reports

CVE List Score used 3.3

accountsservice drops ruid, allows unprivileged users to send it signals

Record: CVE-2020-16126
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Weakness: CWE-269
Updated: 2026-11-02

EUVDEUVD-2020-8092 3.3

Record: EUVD-2020-8092
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-03

GitHub AdvisoriesGHSA-37qh-6xc5-7fm4 No score

An Ubuntu-specific modification to AccountsService in versions before 0.6.55-0ubuntu13.2, among...

Record: GHSA-37qh-6xc5-7fm4
Updated: 2026-11-02

NVD 3.3

Record: CVE-2020-16126
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0: 2.1 LowAV:L/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-269
Updated: 2026-11-02

OSVUBUNTU-CVE-2020-16126 3.3

Record: UBUNTU-CVE-2020-16126
CVSS 3.1: 3.3 LowCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-02

OSVUSN-4616-1 No score

accountsservice vulnerabilities

Kevin Backhouse discovered that AccountsService incorrectly dropped privileges. A local user could possibly use this issue to cause AccountsService to crash or hang, resulting in a denial of service. (CVE-2020-16126)

Kevin Backhouse discovered that AccountsService incorrectly handled reading .pam_environment files. A local user could possibly use this issue to cause AccountsService to crash or hang, resulting in a denial of service. This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. (CVE-2020-16127)

Matthias Gerstner discovered that AccountsService incorrectly handled certain path checks. A local attacker could possibly use this issue to read arbitrary files. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2018-14036)

Record: USN-4616-1
Updated: 2026-11-02

OSVUSN-4616-2 No score

accountsservice vulnerabilities

USN-4616-1 fixed several vulnerabilities in AccountsService. This update provides the corresponding update for Ubuntu 14.04 ESM.

Original advisory details:

Matthias Gerstner discovered that AccountsService incorrectly handled certain path checks. A local attacker could possibly use this issue to read arbitrary files. (CVE-2018-14036)

Record: USN-4616-2
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`accountsservice` Ubuntu:Pro:14.04:LTS	before 0.6.35-0ubuntu7.3+esm2, plus listed versions 0.6.34-0ubuntu60.6.34-0ubuntu70.6.35-0ubuntu10.6.35-0ubuntu20.6.35-0ubuntu3 Show 7 moreShow less 0.6.35-0ubuntu40.6.35-0ubuntu50.6.35-0ubuntu60.6.35-0ubuntu70.6.35-0ubuntu7.10.6.35-0ubuntu7.20.6.35-0ubuntu7.3	0.6.35-0ubuntu7.3+esm2
`accountsservice` Ubuntu:16.04:LTS	before 0.6.40-2ubuntu11.6, plus listed versions 0.6.40-2ubuntu50.6.40-2ubuntu60.6.40-2ubuntu70.6.40-2ubuntu80.6.40-2ubuntu9 Show 5 moreShow less 0.6.40-2ubuntu100.6.40-2ubuntu110.6.40-2ubuntu11.10.6.40-2ubuntu11.20.6.40-2ubuntu11.3	0.6.40-2ubuntu11.6
`accountsservice` Ubuntu:18.04:LTS	before 0.6.45-1ubuntu1.3, plus listed versions 0.6.42-0ubuntu30.6.42-0ubuntu40.6.45-1ubuntu1	0.6.45-1ubuntu1.3
`accountsservice` Ubuntu:20.04:LTS	before 0.6.55-0ubuntu12~20.04.4, plus listed versions 0.6.55-0ubuntu100.6.55-0ubuntu110.6.55-0ubuntu12~20.04.10.6.55-0ubuntu12~20.04.2	0.6.55-0ubuntu12~20.04.4

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	zev3n/Ubuntu-Gnome-privilege-escalation	2020-11-12

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, products	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-16126 is a low vulnerability (CVSS 3.3) in Freedesktop Accountsservice, published November 3, 2020. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.54%, the 45th percentile. Fixed in accountsservice 0.6.35-0ubuntu7.3+esm2.