How severe is CVE-2019-5077?

CVE-2019-5077 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2019-5077 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-5077?

CVE-2019-5077 primarily affects Wago Pfc 200 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-5077?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2019-5077 published?

CVE-2019-5077 was published on 2019-12-18 and last updated on 2026-06-17.

CVE-2019-5077

CVE-2019-5077 is a critical-severity vulnerability in Wago Pfc 200 Firmware with a CVSS 3.x base score of 9.1. 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-306.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 8.5
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-306
Affected product: Wago Pfc 200 Firmware
Published: 2019-12-18
Last modified: 2026-06-17

Description

An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC 100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a denial of service, resulting in the device entering an error state where it ceases all network communications. An attacker can send unauthenticated packets to trigger this vulnerability.

Frequently asked questions

What is CVE-2019-5077?: An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC 100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a denial of service, resulting in the device entering an error state where it ceases all network communications. An attacker can send unauthenticated packets to trigger this vulnerability.
How severe is CVE-2019-5077?: CVE-2019-5077 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2019-5077 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-5077?: CVE-2019-5077 primarily affects Wago Pfc 200 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5077?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-5077 published?: CVE-2019-5077 was published on 2019-12-18 and last updated on 2026-06-17.

References

https://talosintelligence.com/vulnerability_reports/TALOS-2019-0869

Affected products (3)

cpe:2.3:o:wago:pfc_200_firmware:03.00.39\(12\):*:*:*:*:*:*:*
cpe:2.3:o:wago:pfc_200_firmware:03.01.07\(13\):*:*:*:*:*:*:*
cpe:2.3:o:wago:pfc_100_firmware:03.00.39\(12\):*:*:*:*:*:*:*

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