Credential disclosure via plaintext database passwords
Published Apr 9, 2026 · Updated Apr 9, 2026
Plaintext password storage in all OpenPLC Runtime v3 versions allows remote attackers to retrieve credentials from its database. The webserver reads password values from the Users table in openplc.db and compares submitted passwords directly against them, leaving credentials recoverable as plaintext. CISA identifies network reachability without prior privileges but does not disclose the additional condition required to obtain the database.
Summary
What happened
Plaintext password storage in all OpenPLC Runtime v3 versions allows remote attackers to retrieve credentials from its database. The webserver reads password values from the Users table in openplc.db and compares submitted passwords directly against them, leaving credentials recoverable as plaintext. CISA identifies network reachability without prior privileges but does not disclose the additional condition required to obtain the database.
The record
- CVE
- CVE-2026-35556
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- OpenPLC Project
- Product
- OpenPLC Runtime
- Classifications
- CWE-256, T1552.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=All versions
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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