CVE-2016-9928: MCabber before 1.0.4 is vulnerable to roster push attacks, which allows remote attackers to intercept communic

This week

HIGH 7.4REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2016-9928 is a high-severity flaw (CVSS 7.4) affecting mcabber, ubuntu linux, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

MCabber before 1.0.4 is vulnerable to roster push attacks, which allows remote attackers to intercept communications, or add themselves as an entity on a 3rd party's roster as another user, which will also garner associated privileges, via crafted XMPP packets.

Why this priority

High severity
EPSS top 8%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	4.5% (top 8%)
CISA exploited list	No
Weakness	CWE-269
Published	2020-02-06
Last modified	2026-06-17

Publisher (CNA): Debian GNU/Linux · Vendor: canonical · debian · mcabber

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-02-06 14:15 UTCPublished CVE record published
2026-06-17 00:56 UTCUpdated Record last modified

mcabber mcabber UPGRADE

Affected: >= 1.0.0 and < 1.0.4

Fixed in: 1.0.4

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy mcabber || rpm -q mcabber || mcabber --version

2. UPGRADE to 1.0.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mcabber

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mcabber

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison mcabber sudo apt install mcabber=<VERSION_BEFORE_1.0.0> sudo apt-mark hold mcabber

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mcabber sudo dnf downgrade mcabber-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add mcabber

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

canonical ubuntu linux MITIGATE

Affected: 16.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

debian debian linux MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2016-9928?

mcabber: upgrade to 1.0.4; ubuntu linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-9928 being exploited?

CVE-2016-9928 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2016-9928 affect?

CVE-2016-9928 affects mcabber, ubuntu linux, debian linux. Severity is high (CVSS 7.4). MCabber before 1.0.4 is vulnerable to roster push attacks, which allows remote attackers to intercept communications, or add themselves as an entity on a 3rd party's roster as another user, which will also garner associated privileges, via

How urgent is CVE-2016-9928?

Priority 64/100. High severity; EPSS top 8%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Ubuntu vulnerabilities · Debian vulnerabilities

References

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