CVE-2019-16747: In MatrixSSL before 4.2.2 Open, the DTLS server can encounter an invalid pointer free (leading to memory corru

Q: How do I fix CVE-2019-16747?

matrixssl: upgrade to 4.2.2. Exact commands for each OS are on this page.

Q: Is CVE-2019-16747 being exploited?

CVE-2019-16747 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2019-16747 affect?

CVE-2019-16747 affects matrixssl. Severity is high (CVSS 7.5). In MatrixSSL before 4.2.2 Open, the DTLS server can encounter an invalid pointer free (leading to memory corruption and a daemon crash) via a crafted incoming network message, a different vulnerability than CVE-2019-14431.

Q: How urgent is CVE-2019-16747?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2019-16747 is a high-severity flaw (CVSS 7.5) affecting matrixssl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In MatrixSSL before 4.2.2 Open, the DTLS server can encounter an invalid pointer free (leading to memory corruption and a daemon crash) via a crafted incoming network message, a different vulnerability than CVE-2019-14431.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.8% (top 22%)
CISA exploited list	No
Weakness	CWE-787
Published	2020-12-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: matrixssl

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

Am I affected?

Timeline

2020-12-30 21:15 UTCPublished CVE record published
2026-06-17 02:22 UTCUpdated Record last modified

matrixssl matrixssl UPGRADE

Affected: < 4.2.2

Fixed in: 4.2.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 4.2.2 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade matrixssl

Note

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

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-2019-16747?

matrixssl: upgrade to 4.2.2. Exact commands for each OS are on this page.

Is CVE-2019-16747 being exploited?

CVE-2019-16747 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-2019-16747 affect?

CVE-2019-16747 affects matrixssl. Severity is high (CVSS 7.5). In MatrixSSL before 4.2.2 Open, the DTLS server can encounter an invalid pointer free (leading to memory corruption and a daemon crash) via a crafted incoming network message, a different vulnerability than CVE-2019-14431.

How urgent is CVE-2019-16747?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2023-24609 HIGH 7.5 UPGRADE MITIGATE Matrix SSL 4.x through 4.6.0 and Rambus TLS Toolkit have a length-subtraction integer overflow for Client Hell
CVE-2022-46505 HIGH 7.5 UPGRADE An issue in MatrixSSL 4.5.1-open and earlier leads to failure to securely check the SessionID field, resulting
CVE-2022-43974 HIGH 8.1 UPGRADE MatrixSSL 4.0.4 through 4.5.1 has an integer overflow in matrixSslDecodeTls13
CVE-2019-14431 CRITICAL 9.8 UPGRADE In MatrixSSL 3.8.3 Open through 4.2.1 Open, the DTLS server mishandles incoming network messages leading to a
CVE-2019-13629 MEDIUM 5.9 UPGRADE MatrixSSL 4.2.1 and earlier contains a timing side channel in ECDSA signature generation

References

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