CVE-2026-51541
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in CIP message parsing when handling malformed explicit requests with a forged EPath size. An attacker can send a valid ENIP SendRRData frame carrying a very short CIP payload whose path_size field claims that many more path words are present than are actually available. Because the parser trusts the attacker-controlled path_size and continues decoding path segments without a remaining-length boundary, it reads beyond the end of the stack receive buffer.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOpENer 2.3.0 contains an out-of-bounds read vulnerability in CIP message parsing where the parser trusts an attacker-controlled path_size field in malformed explicit requests. When a SendRRData frame contains a short CIP payload but claims a larger path_size, the parser continues reading path segments beyond the receive buffer boundary, leading to memory disclosure or potential crash.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 2.3.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify OpENer installationLocate the OpENer binary or service on the system. Common locations include /opt/OpENer, /usr/local/OpENer, or check running services for OpENer-related processes.Affected if OpENer version 2.3.0 is installed and running
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Verify OpENer versionCheck the installed version of OpENer. If using a binary, run 'OpENer --version' or check the binary metadata. If source is available, examine version.h or the release tag.Affected if The installed version is exactly 2.3.0 (the only version listed as affected)
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Confirm CIP/EPath processing is enabledExamine the OpENer configuration files or runtime settings to determine if CIP message handling and EPath parsing are active. Look for settings related to CIP, ENIP, or Ethernet/IP processing in the configuration.Affected if CIP message parsing and EPath handling are enabled in the OpENer configuration
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Verify ENIP SendRRData endpoint is accessibleCheck network configuration or firewall rules to determine if the OpENer service is accepting ENIP SendRRData requests on ports 44818 (UDP/TCP) or 2222 (industrial protocol).Affected if The OpENer service is exposed and accepting ENIP SendRRData requests from network sources
A user is affected if OpENer version 2.3.0 is running with CIP/EPath parsing enabled and accessible via network requests.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement proper remaining-length validation before reading path segments based on path_size, ensuring the parser never reads beyond the available payload data.
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-51541 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-51541 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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