CVE-2026-115723

What it is

Snap7 through 1.4.3 contains an out-of-bounds write vulnerability in the passive partner that allows a malicious active partner to overflow application buffers by declaring an unvalidated BSend total length. Attackers connecting from the configured peer address can declare up to 65535 bytes and send a short fragment, causing BRecv to memcpy past the buffer and crash or corrupt SCADA, HMI or gateway processes.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-23 11:26 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-23 12:18 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-23 15:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 8.3 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-10-23 12:18 UTC

Last modified

2026-10-23 15:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Deferred

Attack profile CVSS 4.0 · 8.3

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

None

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-115723.md and follow it. Check whether this project is affected by CVE-2026-115723. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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