CVE-2026-67869
Description
A flaw was found in open62541. A remote attacker can exploit a buffer overflow vulnerability within the Service_Call function. This vulnerability arises from improper validation of input arguments against runtime-resolved InputArguments metadata, which can lead to a denial of service (DoS).
Statement
This Important flaw in open62541 allows a remote, unauthenticated attacker to trigger a denial of service. The vulnerability stems from insufficient validation of input arguments within the Service_Call function, which can lead to a buffer overflow and subsequent service unavailability.
Mitigation
No practical workaround identified beyond restricting NodeManagement / method-metadata
changes to trusted principals and limiting network exposure of the OPC UA server.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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