How severe is CVE-2018-7843?

CVE-2018-7843 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-7843 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-7843?

CVE-2018-7843 primarily affects Schneider-electric Modicon M580 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-2018-7843?

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

When was CVE-2018-7843 published?

CVE-2018-7843 was published on 2019-05-22 and last updated on 2026-06-17.

CVE-2018-7843

CVE-2018-7843 is a high-severity vulnerability in Schneider-electric Modicon M580 Firmware with a CVSS 3.x base score of 7.5. 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Schneider-electric Modicon M580 Firmware
Published: 2019-05-22
Last modified: 2026-06-17

Description

A CWE-248: Uncaught Exception vulnerability exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium which could cause denial of service when reading memory blocks with an invalid data size or with an invalid data offset in the controller over Modbus.

Frequently asked questions

What is CVE-2018-7843?: A CWE-248: Uncaught Exception vulnerability exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium which could cause denial of service when reading memory blocks with an invalid data size or with an invalid data offset in the controller over Modbus.
How severe is CVE-2018-7843?: CVE-2018-7843 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-7843 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-7843?: CVE-2018-7843 primarily affects Schneider-electric Modicon M580 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-2018-7843?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-7843 published?: CVE-2018-7843 was published on 2019-05-22 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:schneider-electric:modicon_m580_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_quantum_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_premium_firmware:*:*:*:*:*:*:*:*

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