CVE-2026-35556
Openplcproject Openplc V3 Firmware
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-35556 is a critical-severity Plaintext Storage of a Password (CWE-256) vulnerability in Openplcproject Openplc V3 Firmware. Its CVSS base score is 9.2 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Credentials In Files (T1552.001); ranked at the 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-28 (Protection of Information at Rest) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-35556 is a Plaintext Storage of a Password vulnerability (CWE-256) in OpenPLC_V3, published on 2026-04-09. The issue enables attackers to retrieve credentials stored in plaintext, potentially granting access to sensitive information. It carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating high confidentiality impact with network accessibility and low attack complexity.
An unauthenticated attacker (PR:N) can exploit this vulnerability remotely over the network (AV:N) without requiring user interaction (UI:N). Exploitation involves accessing the affected component to extract plaintext credentials, allowing unauthorized disclosure of sensitive information (C:H) while leaving integrity and availability unaffected.
The CISA ICS Advisory ICSA-25-345-10 provides further details on this vulnerability, including potential mitigation steps, at https://www.cisa.gov/news-events/ics-advisories/icsa-25-345-10.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21041
Vulnerability Data
OpenPLC_V3 is vulnerable to a Plaintext Storage of a Password vulnerability that could allow an attacker to retrieve credentials and access sensitive information.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requiring confidentiality protection of information at rest directly stops passwords from being stored in plaintext.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Encryption and hashing of data-at-rest directly prevent plaintext password storage in files.
Credential management practices normally include secure storage requirements for passwords.
Protecting data-in-use can limit exposure of passwords held in memory.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Directly requires secure handling and protection of authentication information, preventing plaintext password storage.
Requires use of cryptography to protect sensitive data such as passwords at rest.
Secure coding practices would prevent developers from writing code that stores passwords in plaintext.
Mandates secure authentication mechanisms that inherently require hashed or encrypted credentials rather than plaintext.
Requires secure deletion of sensitive information, indirectly reducing exposure of stored plaintext passwords.