No exploitation reportedFix available

CVE-2020-7539

Q: Is CVE-2020-7539 actively exploited?

Active exploitation of CVE-2020-7539 has not been confirmed. Its EPSS score was 1.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-7539?

CVE-2020-7539 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2020-12-11
Fixed in6.1
WeaknessCWE-754

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A CWE-754 Improper Check for Unusual or Exceptional Conditions vulnerability exists in the Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions), that could cause a denial of service vulnerability when a specially crafted packet is sent to the controller over HTTP.

Timeline

dates in UTC

2020-12-1101:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-7539?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-7539?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Schneider-electric 140cpu65150 firmwareversion to verify

Branch	Affected	Fixed in	Source
6.1	< 6.1	6.1	NVD

Schneider-electric 140noc77101 firmwareversion to verify

Branch	Affected	Fixed in	Source
1.8	< 1.08	1.08	NVD

Schneider-electric 140noc78000 firmwareversion to verify

Branch	Affected	Fixed in	Source
1.74	< 1.74	1.74	NVD

17 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Schneider-electric 140cpu65150 firmware to 6.1

Advisories and patches

www.se.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-754read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-12-11
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-7539?

Is CVE-2020-7539 actively exploited?

Active exploitation of CVE-2020-7539 has not been confirmed. Its EPSS score was 1.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-7539?

CVE-2020-7539 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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