How severe is CVE-2026-6866?

CVE-2026-6866 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 high, integrity none, and availability none.

Is CVE-2026-6866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-6866?

CVE-2026-6866 primarily affects Schneider-electric Ecostruxure Panel Server Pas400 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-6866?

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.

Does CVE-2026-6866 have an EU (EUVD) identifier?

Yes. CVE-2026-6866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29484.

When was CVE-2026-6866 published?

CVE-2026-6866 was published on 2026-05-12 and last updated on 2026-06-24.

CVE-2026-6866

CVE-2026-6866 is a high-severity vulnerability in Schneider-electric Ecostruxure Panel Server Pas400 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-1188.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.2
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29484
Weakness: CWE-1188
Affected product: Schneider-electric Ecostruxure Panel Server Pas400 Firmware
Published: 2026-05-12
Last modified: 2026-06-24

Description

CWE-1188 Initialization of a Resource with an Insecure Default vulnerability exists that could cause unauthorized disclosure of sensitive information when credentials revert to initial settings in rare circumstances, enabling unauthorized authentication using known credentials.

Frequently asked questions

What is CVE-2026-6866?: CWE-1188 Initialization of a Resource with an Insecure Default vulnerability exists that could cause unauthorized disclosure of sensitive information when credentials revert to initial settings in rare circumstances, enabling unauthorized authentication using known credentials.
How severe is CVE-2026-6866?: CVE-2026-6866 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 high, integrity none, and availability none.
Is CVE-2026-6866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-6866?: CVE-2026-6866 primarily affects Schneider-electric Ecostruxure Panel Server Pas400 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-6866?: 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.
Does CVE-2026-6866 have an EU (EUVD) identifier?: Yes. CVE-2026-6866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29484.
When was CVE-2026-6866 published?: CVE-2026-6866 was published on 2026-05-12 and last updated on 2026-06-24.

References

https://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2026-132-04&p_enDocType=Security+and+Safety+Notice&p_File_Name=SEVD-2026-132-04.pdf

Affected products (5)

cpe:2.3:o:schneider-electric:ecostruxure_panel_server_pas400_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:ecostruxure_panel_server_pas600_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:ecostruxure_panel_server_pas600v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:ecostruxure_panel_server_pas800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:ecostruxure_panel_server_pas800v2_firmware:*:*:*:*:*:*:*:*

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