How severe is CVE-2026-51541?

CVE-2026-51541 has a CVSS 3.x base score of 9.1, rated critical 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 high.

Is CVE-2026-51541 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-51541?

CVE-2026-51541 affects Opener Project Opener. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-51541?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-51541 published?

CVE-2026-51541 was published on 2026-07-13 and last updated on 2026-08-11.

CVE-2026-51541

CVE-2026-51541 is a critical-severity vulnerability in Opener Project Opener with a CVSS 3.x base score of 9.1. 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-125.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Opener Project Opener
Published: 2026-07-13
Last modified: 2026-08-11

Description

OpENer 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.

Frequently asked questions

What is CVE-2026-51541?: OpENer 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.
How severe is CVE-2026-51541?: CVE-2026-51541 has a CVSS 3.x base score of 9.1, rated critical 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 high.
Is CVE-2026-51541 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-51541?: CVE-2026-51541 affects Opener Project Opener. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-51541?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-51541 published?: CVE-2026-51541 was published on 2026-07-13 and last updated on 2026-08-11.

References

Affected products (1)

cpe:2.3:a:opener_project:opener:2.3.0:*:*:*:*:*:*:*

More vulnerabilities in Opener Project Opener

CVE-2022-43605 — Critical (CVSS 10.0): An out-of-bounds write vulnerability exists in the SetAttributeList attribute_count_request functionality of EIP Stack…
CVE-2022-43604 — Critical (CVSS 10.0): An out-of-bounds write vulnerability exists in the GetAttributeList attribute_count_request functionality of EIP Stack…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2026-51540 — Critical (CVSS 9.8): OpENer 2.3.0 (master branch up to commit 76b95cf) is vulnerable to a severe memory corruption issue caused by an…
CVE-2020-13556 — Critical (CVSS 9.8): An out-of-bounds write vulnerability exists in the Ethernet/IP server functionality of EIP Stack Group OpENer 2.3 and…
CVE-2026-51538 — Critical (CVSS 9.1): EIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of…

All CVEs affecting Opener Project Opener →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →