Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-73665. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-73665 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-73665. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with database audit logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-73665 using CVSS 9.3, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

criticalInjection

CVE-2026-73665

CVE-2026-73665 — FreePBX UCP: Unauthenticated remote code execution via socket.io namespace auth bypass and AMI action injection

Q: What is CVE-2026-73665?

CVE-2026-73665 is FreePBX UCP: Unauthenticated remote code execution via socket.io namespace auth bypass and AMI action injection. The supplied enrichment data classifies it as Injection mapped to CWE-862 CWE-862.

FreePBX is an open source IP PBX. Prior to 17.0.9, the UCP Node server on ports 8001 and 8003 uses io.use(checkAuth) in node/lib/server.js, but Socket.IO version 4 applies that middleware only to the default namespace. An unauthenticated client can connect to custom namespaces that do not consistently invoke checkAuth in node/lib/auth.js and send crafted event values containing carriage-return or newline characters through the Asterisk Manager Interface action path patched by node/lib/asterisk-manager-patch.js, allowing arbitrary commands to execute as the asterisk service user. This issue is fixed in version 17.0.9.

Published Aug 13, 2026Updated Aug 13, 2026Sources: NVD, FreePBX (CNA), 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

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

FreePBX

ucp

CVSS base

9.3

critical

Remediation

The vendor's own words where we have them.

Upgrade ucp to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

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.
Prioritize based on EPSS, PoC availability, and external exposure.
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.

Vendor	Product	Versions	Status
FreePBX	ucp	< 17.0.9	Vulnerable

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Source
9.3	CVSS 4.0	critical	—	—	FreePBX (CNA)

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

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-862 · Missing Authorization

Read Application Data
Read Files or Directories
Modify Application Data
Modify Files or Directories

Mitigation: Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.

Weakness & attack patterns

CWE-862

Inferred from the weakness class — not observed against this CVE.

CAPEC-66 · SQL InjectionCAPEC-7 · Blind SQL Injection

T1211Exploitation for Defensive Evasion
T1542.002Pre-OS Boot: Component Firmware
T1556Modify Authentication Process

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 /lib/server.js, /lib/auth.js, /lib/asterisk-manager-patch.js.

database audit logs

Timeline

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

2026
Added · CVSS 3.1 9.3
Aug 13, 2026 · NVD
Initial · CVE published
Aug 13, 2026 · NVD

References

1 on the record

github.com/FreePBX/security-reporting/security/advisories/GHSA-37j8-fhxx-9vhp
Exploit, Third Party Advisory, Mitre

Elsewhere on this site

FreePBXevery CVE for this vendor
Injectionsame class
CWE-862other pages naming this weakness

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-2026-73665 is FreePBX UCP: Unauthenticated remote code execution via socket.io namespace auth bypass and AMI action injection, a critical vulnerability affecting ucp from FreePBX. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-73665. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-73665. 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 9.3 describes technical severity, while EPSS 0% 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.