---
id: "CVE-2026-72530"
kind: "vulnerability"
aliases: ["CVE-2026-72530"]
title: "A remote unauthorized attacker with network access via port 4307/TCP to the TrueConf server versions 5.3.X to 5.3.9,\u2026"
severity: "critical"
cvss: 9.5
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "trueconf server", "fixed": ["5.3.9.10013"], "affected": "< 5.3.9.10013", "ecosystem": "vendor"}, {"name": "trueconf server", "fixed": ["5.3.9.10015"], "affected": "< 5.3.9.10015", "ecosystem": "vendor"}, {"name": "trueconf server", "fixed": ["5.4.9.10072"], "affected": ">= 5.4.0.12689, < 5.4.9.10072", "ecosystem": "vendor"}, {"name": "trueconf server", "fixed": ["5.4.9.10019"], "affected": ">= 5.4.0.12700, < 5.4.9.10019", "ecosystem": "vendor"}, {"name": "trueconf server", "fixed": ["5.5.5.10010"], "affected": ">= 5.5.0.13826, < 5.5.5.10010", "ecosystem": "vendor"}, {"name": "trueconf server", "fixed": ["5.5.5.10009"], "affected": ">= 5.5.0.13828, < 5.5.5.10009", "ecosystem": "vendor"}, {"name": "TrueConf Server", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "self-hosted", "trueconf-server", "vendor", "windows"]
not_affected_if: ["port-4307-not-exposed", "product-not-installed"]
published_at: "2026-08-19T17:21:01+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:50+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-72530", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72530", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# A remote unauthorized attacker with network access via port 4307/TCP to the TrueConf server versions 5.3.X to 5.3.9,…

TrueConf Server has a code injection flaw that lets an unauthenticated remote attacker on the network reach port 4307/TCP, send a crafted script, escape the isolated environment, and run arbitrary code on the host. CISA lists it as actively exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:trueconf server affected < 5.3.9.10013 fixed 5.3.9.10013
- vendor:trueconf server affected < 5.3.9.10015 fixed 5.3.9.10015
- vendor:trueconf server affected >= 5.4.0.12689, < 5.4.9.10072 fixed 5.4.9.10072
- vendor:trueconf server affected >= 5.4.0.12700, < 5.4.9.10019 fixed 5.4.9.10019
- vendor:trueconf server affected >= 5.5.0.13826, < 5.5.5.10010 fixed 5.5.5.10010
- vendor:trueconf server affected >= 5.5.0.13828, < 5.5.5.10009 fixed 5.5.5.10009
- vendor:TrueConf Server affected ? fixed ?

## How to check

Check whether TrueConf Server is running and listening on 4307/TCP (for example: ss -tlnp | grep 4307 on Linux, or netstat -ano | findstr 4307 on Windows).

## Fix

Apply the vendor mitigation or patch per TrueConf instructions; CISA's required action is to follow BOD 26-04 guidance, or discontinue use if no mitigation is available.
Restrict network access to port 4307/TCP to trusted hosts until patched.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-72530
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-72530

## From the sources

TrueConf Server contains a code injection vulnerability that could allow an unauthorized remote attacker with network access via port 4307/TCP to use a specially crafted script to break out of the isolated environment and execute arbitrary code on the host system.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_