CVE-2026-90572
MediumCVSS 4.7Exploitation Probability (EPSS)
Low risk34th percentile - higher than 34% of all known CVEs
Summary
A vulnerability was determined in davenardella snap7 up to 1.4.3 in the TSnap7MicroClient::opUpload function of src/core/s7_micro_client.cpp. Manipulation of the DataLen argument can lead to memory corruption. The attack can be executed remotely and the exploit has been publicly disclosed. The project was informed but has not responded.
Risk Assessment
A remote attacker can trigger memory corruption, potentially leading to a crash or arbitrary code execution in the application context. The lack of project response increases the risk.
Recommendation
Monitor the project for patches or apply mitigations such as restricting network access to the service. Consider using an alternative library for PLC communication.
Other vulnerabilities in snap7
See all- CVE-2026-16225Medium
A security flaw in snap7 up to version 1.4.3 involves an out-of-bounds write in the TSnap7Peer::NegotiatePDULength function. The attack can be executed remotely by manipulating the PDULength argument.
- CVE-2026-15105Medium
davenardella snap7 up to version 1.4.3 contains an out-of-bounds write vulnerability in the TS7Worker::PerformFunctionRead function. The attack requires local network access. An exploit has been published and may be used.
- CVE-2026-51218High
A heap buffer overflow was discovered in the TS7Worker::PerformFunctionWrite() function (/core/s7_server.cpp) of snap7 v1.4.3. This vulnerability allows an attacker to cause a Denial of Service (DoS) by sending a crafted packet.
- CVE-2020-22552High
In Snap7 server version 1.4.1, a vulnerability allows an attacker to send a crafted packet with the COTP protocol where the last-data-unit flag is set to No and the S7 writes a var function, causing the Snap7 server to crash.
Original NVD description (English source)
A vulnerability was determined in davenardella snap7 up to 1.4.3. The affected element is the function TSnap7MicroClient::opUpload of the file src/core/s7_micro_client.cpp. Executing a manipulation of the argument DataLen can lead to memory corruption. The attack can be executed remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS