Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-89026

Issabel Framework Hard coded JWT Key RCE Remote Code Execution

Issabel / Issabel Framework · affected before b97dbaf0b71c1c36f841e672b664afbeb02773bd

View live feed Monitor via API Watch CVE-2026-89026
Severity
CVSS 9.3 · Critical
Confidence
High
Exploit status
Exploited in the wild
EPSS
0.5%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-89026 is an unauthenticated vulnerability affecting Issabel Issabel Framework. The Issabel Framework, the web framework supporting Issabel PBX software, before commit b97dbaf contains a hard-coded HS256 JWT...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

Issabel / Issabel Framework affected before b97dbaf0b71c1c36f841e672b664afbeb02773bd.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Issabel Framework Hard coded JWT Key RCE Remote Code Execution

The Issabel Framework, the web framework supporting Issabel PBX software, before commit b97dbaf contains a hard-coded HS256 JWT signing key in the pbxapi index.php file that is identical across every installation, allowing unauthenticated remote attackers to forge valid bearer tokens. Attackers can use the forged token to call the manager originate endpoint with the System application parameter, causing Asterisk to execute arbitrary OS commands as the Asterisk user.

Exploitation evidence was first observed by the Shadowserver Foundation on 2026-09-09.

Issabel Foundation Affected
Issabel Framework
Before b97dbaf0b71c1c36f841e672b664afbeb02773bd
View vendor advisory (opens in new tab)
Published
15 Sep 2026
Exploitation Reported
15 Sep 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

php

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-89026
  • Patch Commit github.com · Patch https://github.com/IssabelFoundation/framework/commit/b97dbaf0b71c1c3...
  • Third-Party Advisory — vulncheck.com vulncheck.com · Third-Party Advisory https://www.vulncheck.com/advisories/issabel-pbx-hard-coded-jwt-key-r...

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 15 Sep 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 16 Sep 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-09-15 16:50 UTC
TheHackerNews 2026-09-16 15:50 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

0.5%

Weaknesses

Use of Hard-coded Cryptographic Key CWE-321

Recent mention · TheHackerNews

Attackers Exploit Issabel Framework Flaw Enabling Unauthenticated OS Command Execution

A critical security flaw in Issabel Framework, a web-based framework for the open-source unified communications PBX software, has come under active exploitation. The vulnerability in question is CVE-2026-89026 (CVSS v3.1 score: 9.8/CVSS v4.0 score: 9.3), which can allow an...

Read full advisory

All CVSS Scores

CVSS v4.0 9.3 Critical

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS v3.1 9.8 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

cflowsec/CVE-2026-89026

github · Created 2026-09-16 17:34:33 UTC · 0 stars · AI assessment 90%

Issabel pbxapi hard coded JWT RCE POC

Timeline

From disclosure to observed exploitation

  1. 17:34 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 15:50 UTC

    KEV confirmed by TheHackerNews

    Exploitation attested by an external source

  3. 16:50 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  4. 16:41 UTC

    CVE published

    Vulnerability disclosed publicly

  5. 16:23 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-89026

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-89026",
  "confidence": "High",
  "cvss_score": 9.3,
  "cvss_estimated": false,
  "epss_score": 0.00521,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}