CVE-2026-115723 davenardella CVE debrief

Who should care

Defenders responsible for SCADA, HMI, or gateway systems using Snap7 should assess their exposure and prioritize verification and patching to prevent potential crashes or corruption.

Why it matters

Defenders should prioritize verifying the affected versions and applying patches or mitigations to prevent potential crashes or corruption of SCADA, HMI, or gateway processes. The vulnerability allows a malicious active partner to overflow application buffers, causing BRecv to memcpy past the buffer. Additional information on exploitation or victim impact is not available.

• Potential crashes or corruption of SCADA, HMI, or gateway processes.
• Verification of affected versions and patching prioritization.
• Implementation of additional security controls to prevent exploitation.
• Monitoring of SCADA, HMI, or gateway processes for potential issues.

Technical summary

The vulnerability in Snap7 through 1.4.3 allows a malicious active partner to declare an unvalidated BSend total length, causing BRecv to memcpy past the buffer and crash or corrupt SCADA, HMI or gateway processes. This vulnerability can be exploited by attackers connecting from the configured peer address, who can declare up to 65535 bytes and send a short fragment, leading to potential crashes or corruption of SCADA, HMI, or gateway processes. Defenders should prioritize verifying the affected versions and applying patches or mitigations to prevent potential crashes or corruption of SCADA, HMI, or gateway processes.

Defensive priority

Defenders should prioritize verifying the affected versions and applying patches or mitigations to prevent potential crashes or corruption of SCADA, HMI, or gateway processes.

Recommended defensive actions

• Verify the version of Snap7 being used and check if it is within the affected range (<= 1.4.3).
• Apply patches or mitigations provided by the vendor, if available.
• Monitor SCADA, HMI, or gateway processes for potential crashes or corruption.
• Implement additional security controls to prevent exploitation, such as network segmentation or access controls.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and potential impact. However, additional information on exploitation or victim impact is not available.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.