CVE-2026-73665: FreePBX is an open source IP PBX

Q: How do I fix CVE-2026-73665?

freepbx: upgrade to 17.0.9. Exact commands for each OS are on this page.

Q: Is CVE-2026-73665 being exploited?

CVE-2026-73665 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-73665 affect?

CVE-2026-73665 affects freepbx. Severity is critical (CVSS 9.8). 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 cl

Q: How urgent is CVE-2026-73665?

Priority 46/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-73665 is a critical-severity flaw (CVSS 9.8) affecting freepbx. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 In

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-862
Published	2026-08-13
Last modified	2026-10-09

Publisher (CNA): GitHub, Inc. · Vendor: sangoma

Last updated 2026-10-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-13 22:17 UTCPublished CVE record published
2026-10-09 19:29 UTCUpdated Record last modified

sangoma freepbx UPGRADE

Affected: < 17.0.9

Fixed in: 17.0.9

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy freepbx || rpm -q freepbx || freepbx --version

2. UPGRADE to 17.0.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade freepbx

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freepbx

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-73665?

freepbx: upgrade to 17.0.9. Exact commands for each OS are on this page.

Is CVE-2026-73665 being exploited?

CVE-2026-73665 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-73665 affect?

CVE-2026-73665 affects freepbx. Severity is critical (CVSS 9.8). 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 cl

How urgent is CVE-2026-73665?

Priority 46/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-45562 HIGH 7.2 UPGRADE FreePBX is an open source IP PBX
CVE-2026-54674 HIGH 8.8 UPGRADE FreePBX is an open source IP PBX
CVE-2026-54675 HIGH 8.8 UPGRADE FreePBX is an open source IP PBX
CVE-2026-54708 HIGH 8.8 UPGRADE FreePBX is an open source IP PBX
CVE-2026-54710 HIGH 8.8 UPGRADE FreePBX is an open source IP PBX

References

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