Raw vector
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:XSummary
CVE-2026-28209 is a high-severity OS Command Injection (CWE-78) vulnerability in Sangoma Freepbx. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-28209 is a command injection vulnerability (CWE-78) in FreePBX, an open source IP PBX software. It affects versions 16.0.17.2 up to but not including 16.0.20, and versions 17.0.2.4 up to but not including 17.0.5, specifically when using the ElevenLabs Text-to-Speech (TTS) engine in the recordings module. The vulnerability carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) and was published on 2026-03-05.
The vulnerability can be exploited over the network by an attacker with high privileges (PR:H), requiring low attack complexity and no user interaction. Successful exploitation enables high-impact compromise of confidentiality, integrity, and availability, allowing arbitrary command execution on the affected FreePBX system.
FreePBX has patched the issue in versions 16.0.20 and 17.0.5. Additional details are available in the security advisory at https://github.com/FreePBX/security-reporting/security/advisories/GHSA-f558-mp87-58vj.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9856
Vulnerability Data
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…
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has been patched in versions 16.0.20 and 17.0.5.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.2.5V1.2.8V15.2.5
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least privilege reduces the permissions available to any process that could be subverted by injected commands.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.