---
title: "CVE-2016-20011\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2016-20011?format=md
keywords: index, follow
---

# CVE-2016-20011

Publication date 25 May 2021

Last updated 26 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-20011?format=md#impact-score)

Toggle side navigation

## Description

libgrss through 0.7.0 fails to perform TLS certificate verification when
downloading feeds, allowing remote attackers to manipulate the contents of
feeds without detection. This occurs because of the default behavior of
SoupSessionSync.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| libgrss | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 25.04 plucky | Not in release |
| 24.10 oracular | Not in release |
| 24.04 LTS noble | Needs evaluation |
| 23.10 mantic | Ignored end of life, was needs-triage |
| 23.04 lunar | Ignored end of life, was needs-triage |
| 22.10 kinetic | Ignored end of life, was needs-triage |
| 22.04 LTS jammy | Needs evaluation |
| 21.10 impish | Ignored end of life |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2016-20011?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| libgrss | * Upstream:   <https://gitlab.gnome.org/GNOME/libgrss/-/merge_requests/7> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | High |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-20011)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-20011)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-20011)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-20011)

### Other references

* <https://bugzilla.gnome.org/show_bug.cgi?id=772647>
* <https://gitlab.gnome.org/GNOME/libgrss/-/issues/4>
* <https://www.cve.org/CVERecord?id=CVE-2016-20011>