CVE-2019-9583: eQ-3 Homematic CCU2 and CCU3 obtain session IDs without login

This week

HIGH 8.2REMOTEMITIGATEMITIGATE

CVE-2019-9583 is a high-severity flaw (CVSS 8.2) affecting homematic ccu3 firmware, homematic ccu2 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

eQ-3 Homematic CCU2 and CCU3 obtain session IDs without login. This allows a Denial of Service and is a starting point for other attacks. Affected versions for CCU2: 2.35.16, 2.41.5, 2.41.8, 2.41.9, 2.45.6, 2.45.7, 2.47.10, 2.47.12, 2.47.15. Affected versions for CCU3: 3.41.11, 3.43.16, 3.45.5, 3.45.7, 3.47.10, 3.47.15.

Why this priority

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

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.9% (top 21%)
CISA exploited list	No
Weakness	CWE-400
Published	2019-08-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: eq-3

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

Am I affected?

Timeline

2019-08-14 20:15 UTCPublished CVE record published
2026-06-17 02:43 UTCUpdated Record last modified

eq-3 homematic ccu3 firmware MITIGATE

Affected: 3.41.11 · 3.43.16 · 3.45.5 · 3.45.7 · 3.47.10 · 3.47.15

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.41.11

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.

eq-3 homematic ccu2 firmware MITIGATE

Affected: all versions · 2.35.16 · 2.41.5 · 2.41.8 · 2.41.9 · 2.45.6 · 2.45.7 · 2.47.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.35.16

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-2019-9583?

homematic ccu3 firmware: mitigate or apply the listed mitigation; homematic ccu2 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-9583 being exploited?

CVE-2019-9583 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-2019-9583 affect?

CVE-2019-9583 affects homematic ccu3 firmware, homematic ccu2 firmware. Severity is high (CVSS 8.2). eQ-3 Homematic CCU2 and CCU3 obtain session IDs without login. This allows a Denial of Service and is a starting point for other attacks. Affected versions for CCU2: 2.35.16, 2.41.5, 2.41.8, 2.41.9, 2.45.6, 2.45.7, 2.47.10, 2.47.12, 2.47.15

How urgent is CVE-2019-9583?

Priority 59/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-33032 CRITICAL 10.0 UPGRADE UPGRADE A Remote Code Execution (RCE) vulnerability in the WebUI component of the eQ-3 HomeMatic CCU2 firmware up to a
CVE-2019-9585 CRITICAL 9.8 UPGRADE UPGRADE eQ-3 Homematic CCU2 prior to 2.47.10 and CCU3 prior to 3.47.10 JSON API has Improper Access Control for Interf
CVE-2019-9584 CRITICAL 9.8 UPGRADE UPGRADE eQ-3 Homematic AddOn 'CloudMatic' on CCU2 and CCU3 allows uncontrolled admin access, resulting in the ability
CVE-2019-18939 CRITICAL 9.8 DOWNGRADE MITIGATE eQ-3 Homematic CCU2 2.47.20 and CCU3 3.47.18 with the HM-Print AddOn through 1.2a installed allow Remote Code
CVE-2019-18938 CRITICAL 9.8 DOWNGRADE MITIGATE eQ-3 Homematic CCU2 2.47.20 and CCU3 3.47.18 with the E-Mail AddOn through 1.6.8.c installed allow Remote Code

References

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