---
title: "CVE-2026-72529: TrueConf Server Missing Authentication for Critical Function Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-72529/
description: "CVE-2026-72529 (TrueConf Server): Exploited in the wild (CISA KEV). A remote unauthorized attacker with network access via port 4307/TCP to the TrueConf…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-19
date_modified: 2026-08-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-72529"
kev: true
cvss: 9.3
epss: 0.01464
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-72529: TrueConf Server Missing Authentication for Critical Function Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run TrueConf Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-08-20, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-08-23 ; treat that as the outer limit, not the target.
- EPSS 1.5% , percentile 73: FIRST’s model estimates a 1.5% chance of exploitation activity in the next 30 days, higher than 73% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Check exposure. TrueConf Server: Exploited Pre-Auth RCE Chain on Port 4307 — Only organizations that run TrueConf Server, or whose staff join meetings on other companies' TrueConf servers, are exposed; for them an unpatched, reachable server should be treated as compromised, because the chain is unauthenticated, yields SYSTEM and was used to infect the server's own users.

## What it is

A remote unauthorized attacker with network access via port 4307/TCP to the TrueConf server versions 5.3.X to 5.3.9, 5.4.X to 5.4.9, 5.5.X to 5.5.5, and earlier could execute an arbitrary script by calling an undocumented function.

## Affected products (CVE record)

- TrueConf TrueConf Server: < 5.3, 5.3 < 5.3.9, 5.4 < 5.4.9, 5.5 < 5.5.5

## Severity

- Kaspersky CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
- Kaspersky CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2026-08-20; federal due date 2026-08-23. Known ransomware use: Unknown.
- 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.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.46% probability of exploitation activity in the next 30 days; percentile 73.

## Sources

- [Listed in CISA KEV notes (trueconf.com)](https://trueconf.com/blog/news/security-fixes-updates-and-advisories)
- [Listed in CISA KEV notes (ics-cert.kaspersky.com)](https://ics-cert.kaspersky.com/advisories/2026/08/11/trueconf-server-missing-authentication-for-critical-function/)
- [CVE.org record CVE-2026-72529](https://www.cve.org/CVERecord?id=CVE-2026-72529)
- [NVD entry CVE-2026-72529](https://nvd.nist.gov/vuln/detail/CVE-2026-72529)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-72529)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk)
- [securelist.com](https://securelist.com/tr/head-mare-targets-trueconf-server-with-phantomcore/120988/)

---
Source page: https://erroneo.us/security/cve/CVE-2026-72529/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt