CISA KEV · Known exploitedCritical

CVE-2026-72529

TrueConf TrueConf Server, trueconf server

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.

CVSS
9.3
EPSS
-
- percentile
CISA KEV
Listed
Published
2026.08.20
PRIORITY ASSESSMENT

Immediate action

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV
Exploit probability-
Technical severityCVSS 9.3

Vulnerability overview

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 product and versions

Product
TrueConf TrueConf Server, trueconf server
Affected versions
< 5.3, >= 5.3 < 5.3.9, >= 5.4 < 5.4.9, >= 5.5 < 5.5.5, < 5.3.9.10013, < 5.3.9.10015, >= 5.4.0.12689 < 5.4.9.10072, >= 5.4.0.12700 < 5.4.9.10019, >= 5.5.0.13826 < 5.5.5.10010, >= 5.5.0.13828 < 5.5.5.10009
Fixed versions
Verify the fixed release separately for each affected product line

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
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.

Due date: 2026.08.23
  1. 1
    Identify

    Confirm that TrueConf TrueConf Server, trueconf server and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE
CWE-306
KEV added
2026.08.20
Ransomware use
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