CVE-2026-73660: FreePBX tts advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

FreePBX is an open source IP PBX. Prior to 16.0.6 and 17.0.5.4, the FreePBX Text-To-Speech module allows an authenticated administrator to save a TTS destination name that is HTML-encoded for storage, decoded during dialplan generation, passed as an AGI argument, and used to build filenames inside agi-bin/propolys-tts.agi. The TTS destination name reaches a raw shell-command execution path, allowing arbitrary operating-system command execution as the asterisk service user. This issue is fixed in versions 16.0.6 and 17.0.5.4.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-08-13).

Weakness: CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)

How it can be exploited

Exploitable over the network with low attack complexity only when specific conditions are present needing high privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. 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

CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: total.

Public exploit evidence (Exploit Observer)

Exploit Observer found 3 code repositories naming this CVE.

Code repositories that name a CVE are often scanners, copies or fakes, and some are malware. Read the code before running anything.

See all 5 references on Exploit Observer

Live scores

EPSS: 0.008
low predicted chance of attack
VEDAS: 0.985
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Suricata

Who is affected

Product	Affected	Not affected
FreePBX tts	version < 16.0.6 version >= 17.0.1, < 17.0.5.4	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-73660 FreePBX - Authenticated OS Command Injection via Text-To-Speech entry name. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-73660 FreePBX - Authenticated OS Command Injection via Text-To-Speech entry name"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"config.php"; nocase; content:"display=tts"; nocase; fast_pattern; http.request_body; content:"name="; nocase; pcre:"/(?:^|&)name=[^&]{0,120}(?:\x24\x28|\x60|\x3b|\x7c|%24%28|%60|%3b|%7c)/i"; classtype:web-application-attack; reference:cve,CVE-2026-73660; reference:url,https://www.exploit.observer/?keyword=CVE-2026-73660&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=freepbx&match=exact; sid:1095806; rev:1;)

CVE-2026-73660.rules on GitHub

References

Other references

https://github.com/FreePBX/security-reporting/security/advisories/GHSA-hg3v-m857-mvw9 (x_refsource_CONFIRM)
https://github.com/FreePBX/tts/commit/37cf0dd3e9ceb4a32e09a2fca6a145320245c0a0 (x_refsource_MISC)
https://github.com/FreePBX/tts/commit/4057410439e66d8be2b47c6358de5fab498bbc21 (x_refsource_MISC)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.