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CISA KEVcriticalAuth Bypasspublic exploit

CVE-2026-72529

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

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.

Published Updated Sources: NVD, TrueConf (CNA), CISA, FIRST EPSS, GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Aug 20, 2026

EPSS

2%

ahead of 73% of scored CVEs

Affects

TrueConf

4 products listed

CVSS base

9.8

critical · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Update TrueConf server to versions 5.3.9, 5.4.9 or 5.5.5.

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.

Federal deadline Aug 23, 2026 — passed 7 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

  • Identify exposed assets running affected vendor/product/version combinations.
  • Treat as emergency remediation because CISA KEV status is present.
  • Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

VendorProductVersionsStatus
TrueConfTrueConf Server* to < 5.3Vulnerable
TrueConfTrueConf Server5.3 to < 5.3.9Vulnerable
TrueConfTrueConf Server5.4 to < 5.4.9Vulnerable
TrueConfTrueConf Server5.5 to < 5.5.5Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactSource
9.8CVSS 3.1critical3.95.9kaspersky.com (CNA), TrueConf (CNA)
9.3CVSS 4.0criticalTrueConf (CNA)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-306 · Missing Authentication for Critical Function

  • Gain Privileges or Assume Identity
  • Other

Mitigation: Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability. Identify all potential communication channels, or other means of interaction with the software, to ensure that all channels are appropriately protected. Developers sometimes perform authentication at the primary channel, but open up a secondary channel that is assumed to be private. For example, a login mechanism may be listening on one network port, but after successful authentication, it may open up a second port where it waits for the connection, but avoids authentication because it assumes that only the authenticated party will connect to the port. In general, if the software or protocol allows a single session or user state to persist across multiple connections or channels, authentication and appropriate credential management need to be used throughout.

Weakness & attack patterns

  • CWE-306Missing Authentication for Critical Function

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-36 · Using Unpublished InterfacesCAPEC-62 · Cross Site Request ForgeryCAPEC-12 · Choosing Message IdentifierCAPEC-166 · Force the System to Reset Values

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

Listed

Aug 20, 2026

Federal deadline

Aug 23, 2026

passed 7 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

1

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

  • Search application, proxy, and WAF logs for requests touching /TCP.
  • Prioritize edge telemetry for network-reachable TrueConf Server.
  • Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.
web/proxy/WAF logsapplication logsnetwork IDS/IPSidentity provider logsauthentication audit logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

  1. 2026
  2. Added to CISA KEV catalog

    Aug 20, 2026 · CISA

  3. Added · CVSS 3.1 9.8 (AV:N)

    Aug 19, 2026 · NVD

  4. Initial · CVE published

    Aug 19, 2026 · NVD

  5. Reported · Advisory published by Kaspersky ICS CERT

    Aug 7, 2026 · TrueConf

  6. Reported · Issue confirmed by TrueConf

    Aug 4, 2026 · TrueConf

  7. Issue discovered by Kaspersky ICS CERT and reported to TrueConf

    Aug 3, 2026 · TrueConf

References

7 on the record

Elsewhere on this site

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1

What should defenders know first?

CVE-2026-72529 is TrueConf Server Missing Authentication for Critical Function Vulnerability, a critical vulnerability affecting TrueConf Server from TrueConf. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.8 describes technical severity, while EPSS 2% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.