CVE-2026-89026
CRITICALDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
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CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 43% of all known CVEs.
References
Related Vulnerabilities
Other CWE-321 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-30406 | Critical | 9.0 | 94% | KEV | Fix |
| CVE-2016-4437 | Critical | 9.8 | 93% | KEV | Fix |
| CVE-2023-32169 | Critical | 9.8 | 56% | - | - |
| CVE-2023-27584 | Critical | 9.8 | 34% | - | Fix |
| CVE-2020-10884 | High | 8.8 | 26% | - | - |
| CVE-2021-4228 | Medium | 5.8 | 9.9% | - | - |
Common questions
How do I fix CVE-2026-89026?
No published fix for CVE-2026-89026 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-89026 being actively exploited?
Not that we know of. CVE-2026-89026 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.52% is the estimated probability that it will be exploited in the next 30 days. That is higher than 43% of all scored CVEs.
How severe is CVE-2026-89026?
CVE-2026-89026 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-17.