How severe is CVE-2026-35556?

CVE-2026-35556 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-2026-35556 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-2026-35556?

CVE-2026-35556 affects Openplcproject Openplc V3 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35556?

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-2026-35556 have an EU (EUVD) identifier?

Yes. CVE-2026-35556 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21041.

When was CVE-2026-35556 published?

CVE-2026-35556 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-35556

CVE-2026-35556 is a high-severity vulnerability in Openplcproject Openplc V3 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-256.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 9.2
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21041
Weakness: CWE-256
Affected product: Openplcproject Openplc V3 Firmware
Published: 2026-04-09
Last modified: 2026-06-17

Description

OpenPLC_V3 is vulnerable to a Plaintext Storage of a Password vulnerability that could allow an attacker to retrieve credentials and access sensitive information.

Frequently asked questions

What is CVE-2026-35556?: OpenPLC_V3 is vulnerable to a Plaintext Storage of a Password vulnerability that could allow an attacker to retrieve credentials and access sensitive information.
How severe is CVE-2026-35556?: CVE-2026-35556 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-2026-35556 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-2026-35556?: CVE-2026-35556 affects Openplcproject Openplc V3 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35556?: 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-2026-35556 have an EU (EUVD) identifier?: Yes. CVE-2026-35556 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21041.
When was CVE-2026-35556 published?: CVE-2026-35556 was published on 2026-04-09 and last updated on 2026-06-17.

References

https://www.cisa.gov/news-events/ics-advisories/icsa-25-345-10

Affected products (1)

cpe:2.3:o:openplcproject:openplc_v3_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Openplcproject Openplc V3 Firmware

CVE-2026-28205 — Critical (CVSS 9.8): OpenPLC_V3 is vulnerable to an Initialization of a Resource with an Insecure Default vulnerability which could allow an…
CVE-2018-20818 — Critical (CVSS 9.8): A buffer overflow vulnerability was discovered in the OpenPLC controller, in the OpenPLC_v2 and OpenPLC_v3 versions. It…
CVE-2024-34026 — Critical (CVSS 9.0): A stack-based buffer overflow vulnerability exists in the OpenPLC Runtime EtherNet/IP parser functionality of OpenPLC…
CVE-2026-35063 — High (CVSS 8.8): OpenPLC_V3 REST API endpoint checks for JWT presence but never verifies the caller's role. Any authenticated user with…
CVE-2021-31630 — High (CVSS 8.8): Command Injection in Open PLC Webserver v3 allows remote attackers to execute arbitrary code via the "Hardware Layer…
CVE-2024-39590 — High (CVSS 7.5): Multiple invalid pointer dereference vulnerabilities exist in the OpenPLC Runtime EtherNet/IP parser functionality of…

All CVEs affecting Openplcproject Openplc V3 Firmware →

Other CWE-256 vulnerabilities

CVE-2024-55026 — Critical (CVSS 9.8): An issue in the reset_pj.cgi endpoint of Weintek cMT-3072XH2 easyweb v2.1.53, OS v20231011 allows unauthorized…
CVE-2025-6561 — Critical (CVSS 9.8): Certain hybrid DVR models ((HBF-09KD and HBF-16NK)) from Hunt Electronic have an Exposure of Sensitive Information…
CVE-2025-6560 — Critical (CVSS 9.8): Multiple wireless router models from Sapido have an Exposure of Sensitive Information vulnerability, allowing…
CVE-2025-5893 — Critical (CVSS 9.8): Smart Parking Management System from Honding Technology has an Exposure of Sensitive Information vulnerability,…
CVE-2025-27662 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) before Virtual Appliance Host 22.0.843 Application 20.0.1923 allows Password in…
CVE-2025-27656 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) before Virtual Appliance Host 22.0.862 Application 20.0.2014 allows Password…

Browse all CWE-256 vulnerabilities →