Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:P) | Attack requirements present |
| Privileges required (PR:H) | High privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:H) | High integrity impact |
| Availability (VA:H) | High availability impact |
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/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
About Sangoma Freepbx
CVE-2026-28209 affects Sangoma Freepbx, a product from Sangoma. Before acting, confirm where Sangoma Freepbx runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: FreePBX is an open source IP PBX. From versions 16.0.17.2 to before 16.0.20 and from version 17.0.2.4 to before 17.0.5, a command injection vulnerability exists in FreePBX when using the ElevenLabs Text-to-Speech (TTS) engine in the recordings module. This issue has been patched in versions 16.0.20 and 17.0.5.
The weakness class is OS Command Injection. Untrusted input is passed to the operating system shell, letting an attacker run commands.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Sangoma Freepbx |
| Affected versions | Freepbx from 16.0.17.2 before 16.0.20; Freepbx from 17.0.2.4 before 17.0.5 |
| Published | Mar 5, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Sangoma Freepbx and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Sangoma Freepbx named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Sangoma Freepbx to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-78: OS Command Injection More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
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.
FreePBX is an open source IP PBX. From 16.0.0 until 16.0.11 and 17.0.4, the FreePBX missedcall module places the inbound Caller ID name from crafted SIP From headers into the missedcalllog INSERT in agi-bin/missedcallnotify.php without escaping or bound parameters. An unauthenticated caller can inject SQL when a monitored extension goes unanswered, corrupting the database and modifying FreePBX administrator accounts to obtain unauthorized remote access. This issue is fixed in versions 16.0.11 and 17.0.4.
FreePBX is an open source IP PBX. From 17.0.1 until 17.0.7, the FreePBX Music on Hold module permits dangerous command-line options for /usr/bin/mpg123 and other allowed players in validateCustomConfiguration() in Music.class.php. An authenticated administrator can use options that write files, open control channels, or create Asterisk call files because applicationUsesDisallowedPlayerOption() does not reject those arguments, resulting in arbitrary command execution as the asterisk service user. This issue is fixed in version 17.0.7.
An unauthenticated SQL injection vulnerability exists in Sangoma Switchvox SMB Edition 8.3 (104997). The /pa endpoint processes XML content beginning with <PolycomIPPhone> and directly concatenates the user-controlled PhoneIP value into PostgreSQL queries without sanitization or parameterization. An unauthenticated remote attacker can execute arbitrary SQL statements against the backend PostgreSQL database using a single crafted request, including database operations and remote code execution.
FreePBX is an open source IP PBX. From 15.0.42 to before 16.0.45 and 17.0.7, unauthenticated users may be able to access the User Control Panel (UCP) using hard-coded initial template credentials if these were not immediately changed by the Administrator who enabled UCP. Authenticated access to ACP is required for the initial setup of UCP generic templates, but after that, without further steps by the admin, unauthenticated users may be able to gain access. This vulnerability is fixed in 16.0.45 and 17.0.7.
FreePBX is an open source IP PBX. Prior to 16.0.22 and 17.0.5, the Dashboard module's getcontent AJAX handler includes PHP files based on user-supplied input without path sanitization. The $_REQUEST['rawname'] parameter is concatenated into an include() call with a .class.php suffix, allowing path traversal via ../ sequences to include arbitrary .class.php files from the filesystem. The included file's PHP code executes before the subsequent class instantiation error occurs. This vulnerability is fixed in 16.0.22 and 17.0.5.
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