How severe is CVE-2018-11399?

CVE-2018-11399 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-11399 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-11399?

CVE-2018-11399 primarily affects Simplisafe U9k-es1000 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-11399?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-11399 published?

CVE-2018-11399 was published on 2018-05-24 and last updated on 2026-06-17.

CVE-2018-11399

CVE-2018-11399 is a medium-severity vulnerability in Simplisafe U9k-es1000 Firmware with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-319.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 1.9
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-319
Affected product: Simplisafe U9k-es1000 Firmware
Published: 2018-05-24
Last modified: 2026-06-17

Description

SimpliSafe Original has Unencrypted Sensor Transmissions, which allows physically proximate attackers to obtain potentially sensitive information about the specific times when alarm-system events occur.

Frequently asked questions

What is CVE-2018-11399?: SimpliSafe Original has Unencrypted Sensor Transmissions, which allows physically proximate attackers to obtain potentially sensitive information about the specific times when alarm-system events occur.
How severe is CVE-2018-11399?: CVE-2018-11399 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-11399 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-11399?: CVE-2018-11399 primarily affects Simplisafe U9k-es1000 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-11399?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-11399 published?: CVE-2018-11399 was published on 2018-05-24 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:simplisafe:u9k-es1000_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:simplisafe:u9k-kr1_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:simplisafe:u9k-ms1000_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:simplisafe:u9k-wt1000_firmware:-:*:*:*:*:*:*:*

Other CWE-319 (Cleartext Transmission of Sensitive Information) vulnerabilities

CVE-2025-4378 — Critical (CVSS 10.0): Cleartext Transmission of Sensitive Information, Use of Hard-coded Credentials vulnerability in Ataturk University…
CVE-2025-47419 — Critical (CVSS 10.0): Cleartext Transmission of Sensitive Information vulnerability in Crestron Automate VX allows Sniffing Network…
CVE-2026-48902 — Critical (CVSS 9.8): The password and username reset features created plain http links for https connections if the "Force SSL" flag wasn't…
CVE-2025-34271 — Critical (CVSS 9.8): Nagios Log Server versions prior to 2024R2.0.2 contain a vulnerability in the cluster manager component when…
CVE-2025-32880 — Critical (CVSS 9.8): An issue was discovered on COROS PACE 3 devices through 3.0808.0. It implements a function to connect the watch to a…
CVE-2025-26199 — Critical (CVSS 9.8): CloudClassroom-PHP-Project v1.0 is affected by an insecure credential transmission vulnerability. The application…

Browse all CWE-319 (Cleartext Transmission of Sensitive Information) vulnerabilities →