CVE-2026-15105
MediumCVSS 6.3Exploitation Probability (EPSS)
Low risk21th percentile - higher than 21% of all known CVEs
Summary
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.
Risk Assessment
An attacker on the local network can cause memory corruption, potentially leading to server crash or code execution.
Recommendation
Update snap7 to the latest available version or apply workarounds if the vendor has not yet released a patch.
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-2026-51218High
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 flaw has been found in davenardella snap7 up to 1.4.3. This affects the function TS7Worker::PerformFunctionRead of the file src/core/s7_server.cpp of the component ReadVar Request Handler. This manipulation causes out-of-bounds write. The attack requires access to the local network. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.