api: Shared OAuth Signing Key Between Different Instances

published 2025-09-04 14 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-34015

cvss: 5.1; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits: 0; none known

api is a module for FreePBX@, which is an open source GUI that controls and manages Asterisk© (PBX). In versions lower than 15.0.13, 16.0.2 through 16.0.14, 17.0.1 and 17.0.2, there is an identical OAuth private key used across multiple systems that installed the same FreePBX RPM or DEB package. An attacker with access to the shared OAuth private key could forge JWT tokens, bypass authentication, and potentially gain full access to both REST and GraphQL APIs. Systems with the "api" module enabled, configured and previously activated by an administrator for remote inbound connections may be affected. This issue is fixed in versions 15.0.13, 16.0.15 and 17.0.3.

Patch / fix

fixed in 2 links 1

freepbx api 15.0.13, 16.0.15, 17.0.3
sangoma freepbx 15.0.13, 16.0.15, 17.0.3

github.com/FreePBX/api@305295a commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 14 mo ago (2025-09-05)

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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

Affected products

FreePBX api

Classification

Weakness

CWE-798 Use of Hard-coded Credentials
CWE-522 Insufficiently Protected Credentials

References

Sources

CVE List CVE-2025-55739
NVD CVE-2025-55739

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary