# CVE-2025-40889 — Nozomi Networks Guardian

> As of 2025-10-07, CVE-2025-40889 is a HIGH-severity vulnerability in Nozomi Networks Guardian, CVSS v3.1 8.1, EPSS 0.4% (32.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-40889, most recently “Multiple Vulnerabilities in Nozomi Guardian/CMC Before 25.4.0 on Siemens RUGGEDCOM APE1808 Devices (CVE-2024-13089, CVE-2024-13090, CVE-2025-3719, CVE-2025-40889, et al.)”.

**Last updated:** 2025-10-07

## What is CVE-2025-40889?

A path traversal vulnerability was discovered in the Time Machine functionality due to missing validation of two input parameters. An authenticated user with limited privileges, by issuing a specifically-crafted request, can potentially alter the structure and content of files in the /data folder, and/or affect their availability.

The record classifies CVE-2025-40889 under weakness class [CWE-22](https://intel.threadlinqs.com/cwe/CWE-22). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 368 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.1 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H`)
- **CVSS v4.0 base score:** 7.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 32.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2025-10-07

## Is CVE-2025-40889 being exploited?

Weaponised exploit code for CVE-2025-40889 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 21 in the Threadlinqs vulnerability feed.

- [trickest/cve](https://github.com/trickest/cve/blob/main/2025/CVE-2025-40889.md) (trickest)

## Affected products and versions

- [Nozomi Networks](https://intel.threadlinqs.com/vendors/nozomi-networks): Guardian, CMC

## How to fix CVE-2025-40889

No vendor patch reference has been recorded for CVE-2025-40889 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-2025-40889

1 tracked threat in the Threadlinqs corpus references CVE-2025-40889, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Vulnerabilities in Nozomi Guardian/CMC Before 25.4.0 on Siemens RUGGEDCOM APE1808 Devices (CVE-2024-13089, CVE-2024-13090, CVE-2025-3719, CVE-2025-40889, et al.)](https://intel.threadlinqs.com/threat/TL-2026-2487) — HIGH · 2026-09-13

## Sources

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

**Other references**

- [security.nozominetworks.com](https://security.nozominetworks.com/NN-2025:9-01)

Canonical: https://intel.threadlinqs.com/cve/CVE-2025-40889
Full detection coverage and IOCs for threats exploiting CVE-2025-40889 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp