# CVE-2026-15105 — davenardella snap7

> As of 2026-08-01, CVE-2026-15105 is a MEDIUM-severity vulnerability in davenardella snap7, CVSS v3.1 6.3, EPSS 0.3% (29.6th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-15105, most recently “AI-Powered Attacks Targeting Siemens S7 Series PLCs in U.S. Critical Infrastructure”.

**Last updated:** 2026-08-01

## What is CVE-2026-15105?

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.

The record classifies CVE-2026-15105 under weakness classes [CWE-787](https://intel.threadlinqs.com/cwe/CWE-787), [CWE-119](https://intel.threadlinqs.com/cwe/CWE-119). Its CVSS v3 base vector states that the flaw is reachable from an adjacent network, needs no prior authentication, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 99 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.3 — MEDIUM (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R`)
- **CVSS v4.0 base score:** 5.3 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 29.6% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-08, last modified 2026-08-01

## Is CVE-2026-15105 being exploited?

Weaponised exploit code for CVE-2026-15105 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 27 in the Threadlinqs vulnerability feed.

- [trickest/cve](https://github.com/trickest/cve/blob/main/2026/CVE-2026-15105.md) (trickest)

## Affected products and versions

- **davenardella**: snap7

## How to fix CVE-2026-15105

No vendor patch reference has been recorded for CVE-2026-15105 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-15105

1 tracked threat in the Threadlinqs corpus references CVE-2026-15105, either in the campaign’s CVE list or as an indicator on the campaign record.

- [AI-Powered Attacks Targeting Siemens S7 Series PLCs in U.S. Critical Infrastructure](https://intel.threadlinqs.com/threat/TL-2026-2076) — CRITICAL · 2026-08-19

## Sources

Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10.

**Exploit and proof of concept**

- [github.com — exploit](https://github.com/user-attachments/files/28681740/poc.zip)

**Technical analysis**

- [vuldb.com — vdb entry](https://vuldb.com/vuln/376946)

**Third-party advisory**

- [vuldb.com — signature](https://vuldb.com/vuln/376946/cti)
- [vuldb.com — third party advisory](https://vuldb.com/cve/CVE-2026-15105)
- [vuldb.com — third party advisory (851026)](https://vuldb.com/submit/851026)

**Issue tracking and product pages**

- [github.com — issue tracking](https://github.com/davenardella/snap7/issues/16)
- [github.com — product](https://github.com/davenardella/snap7/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-15105
Full detection coverage and IOCs for threats exploiting CVE-2026-15105 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp